UE(User Equipment)

Abstract

Provided is a means for, when a UE in 5GS cannot be provided with a communication service due to application of a disaster state by a PLMN, transmitting and receiving a notification and for selecting a PLMN for the UE to roam to. Provided are, in 5GS: a procedure for, when a PLMN has applied or removed a disaster state, allowing a UE to recognize the state of the PLMN and to transmit and receive information for appropriately selecting a PLMN to move to; a method for selecting a PLMN on the basis of information received via a notification or the like from the PLMN and stored by the UE; and a communication means.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a UE (User Equipment). This application claims priority to Japanese Patent Application No. 2021-004783, filed on January 15, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] 3GPP (3rd Generation Partnership Project), which is currently working on standardization of mobile communication systems, is currently studying SAE (System Architecture Evolution), which is the system architecture of LTE (Long Term Evolution).

[0003] In recent years, 3GPP has also been studying next-generation communication technologies and system architectures for 5G (5th Generation) mobile communication systems, and in particular has been working on the specification of 5GS (5G System) as a system for realizing 5G mobile communication systems (see Non-Patent Documents 1 to 4). 5GS identifies technical issues for connecting a wide variety of terminals to cellular networks and specifies solutions. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 23.501 V16.7.0 (2020-12); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; System Architecture for the 5G System; Stage 2 (Release 16) [Non-patent document 2] 3GPP TS 23.502 V16.7.0 (2020-12); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Procedures for the 5G System; Stage 2 (Release 16) [Non-patent document 3] 3GPP TS 24.501 V17.1.0 (2020-12); 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 (Release 16) [Non-patent document 4] 3GPP TS 23.122 V17.1.1 (2021-01); 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode (Release 16) [Non-Patent Document 5] 3GPP TR 24.811 V0.1.0 (2020-12); 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Study on the support for minimization of service interruption; (Release 17) Summary of the Invention [Problem to be solved by the invention]

[0005] In 5GS (5G System), a new core network, 5GCN (5G Core Network), is being considered to provide a wide variety of services.

[0006] Furthermore, 3GPP is studying functions related to the core network and UE (User Equipment) in the event that a PLMN (Public Land Mobile Network), which is a communication network that provides mobile communication services, applies a disaster condition and is unable to provide services to the UE (see Non-Patent Document 5).

[0007] However, details such as how a PLMN notifies a UE or other PLMNs when it applies or cancels a disaster state, how a UE recognizes that a PLMN applies or cancels a disaster state, and how a UE selects another PLMN after recognizing that the PLMN to which it is connected is in such a state are not clear.

[0008] One aspect of the present invention has been made in consideration of the above circumstances, and provides a method for notifying a UE when a PLMN applies or cancels a disaster state, and a method for a UE that receives and recognizes the notification to select another PLMN. [Means for solving the problem]

[0009] In one aspect of the present invention, a UE (User Equipment) comprises a transceiver unit and a control unit, wherein the transceiver unit, while registered with a first PLMN (Public Land Mobile Network), receives first identification information from a core network in a first procedure, and the control unit adds the first PLMN to a list managing PLMNs for which access is prohibited based on the reception of the first identification information, and the first identification information is identification information indicating that the first PLMN has applied a disaster state. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide a method for notifying a UE when a PLMN applies or removes a disaster state, and a method for a UE that receives and recognizes the notification to select another PLMN. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an outline of a mobile communication system (EPS / 5GS). [Figure 2] FIG. 1 is a diagram illustrating the detailed configuration of a mobile communication system (EPS / 5GS). [Figure 3] FIG. 1 is a diagram illustrating the device configuration of a UE. [Figure 4] A diagram explaining the configuration of an access network device (gNB) in 5GS. [Figure 5] A diagram explaining the configuration of core network devices (AMF / SMF / UPF) in 5GS. [Figure 6] FIG. 10 is a diagram illustrating a registration procedure. [Figure 7] FIG. 10 is a diagram illustrating a notification procedure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a best mode for carrying out one aspect of the present invention will be described with reference to the drawings. In this embodiment, an embodiment of a mobile communication system to which one aspect of the present invention is applied will be described as an example.

[0013] [1. System Overview] First, FIG. 1 is a diagram for explaining an outline of a mobile communication system 1 used in each embodiment, and FIG. 2 is a diagram for explaining a detailed configuration of the mobile communication system 1. As shown in FIG.

[0014] FIG. 1 shows that the mobile communication system 1 is composed of UE_A10, access network _A80, core network _A90, PDN (Packet Data Network) _A5, access network _B120, core network _B190, and DN (Data Network) _A6.

[0015] In the following, these devices and functions may be referred to by abbreviating the symbols, such as UE, access network_A, core network_A, PDN, access network_B, core network_B, DN, etc.

[0016] Figure 2 also shows devices and functions such as UE_A10, E-UTRAN80, MME40, SGW35, PGW-U30, PGW-C32, PCRF60, HSS50, 5G AN120, AMF140, UPF130, SMF132, PCF160, UDM150, and N3IWF170, as well as interfaces that connect these devices and functions to each other.

[0017] In the following, these devices and functions may be referred to by abbreviated symbols such as UE, E-UTRAN, MME, SGW, PGW-U, PGW-C, PCRF, HSS, 5G AN, AMF, UPF, SMF, PCF, UDM, N3IWF, etc.

[0018] The 4G system EPS (Evolved Packet System) includes an access network A and a core network A, but may further include a UE and / or a PDN. The 5G system 5GS (5G System) includes a UE, an access network B, and a core network B, but may further include a DN.

[0019] A UE is a device that can connect to a network service via 3GPP access (also referred to as a 3GPP access network, or 3GPP AN) and / or non-3GPP access (also referred to as a non-3GPP access network, or non-3GPP AN). A UE may be a terminal device capable of wireless communication, such as a mobile phone or a smartphone, and may be a terminal device that can connect to both EPS and 5GS. A UE may include a UICC (Universal Integrated Circuit Card) or an eUICC (Embedded UICC). Note that a UE may be referred to as a user device or a terminal device.

[0020] Furthermore, access network_A corresponds to an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) and / or a wireless LAN access network. One or more eNBs (evolved Node Bs) 45 are deployed in the E-UTRAN. Note that, hereinafter, the eNB 45 may be referred to by abbreviating the symbol eNB. If there are multiple eNBs, the eNBs are connected to each other, for example, via an X2 interface. Furthermore, one or more access points are deployed in the wireless LAN access network.

[0021] Furthermore, access network_B corresponds to a 5G access network (5G AN). The 5G AN is composed of an NG-RAN (NG Radio Access Network) and / or a non-3GPP access network. One or more gNBs (NR NodeBs) 122 are deployed in the NG-RAN. Note that, hereinafter, the gNB 122 may be referred to by its symbol abbreviated as eNB. The gNB is a node that provides the NR (New Radio) user plane and control plane to UEs and connects to the 5GCN via an NG interface (including an N2 interface or an N3 interface). In other words, the gNB is a base station device newly designed for 5GS, and has different functions from the base station device (eNB) used in the 4G EPS system. Furthermore, when there are multiple gNBs, the gNBs are connected to each other, for example, via an Xn interface.

[0022] Furthermore, the non-3GPP access network may be an untrusted non-3GPP access network or a trusted non-3GPP access network. Here, the untrusted non-3GPP access network may be a non-3GPP access network that does not perform security management within the access network, such as a public wireless LAN. On the other hand, the trusted non-3GPP access network may be an access network specified by 3GPP, and may include a trusted non-3GPP access point (TNAP) and a trusted non-3GPP gateway function (TNGF).

[0023] In the following, E-UTRAN and NG-RAN may be referred to as 3GPP access. Also, wireless LAN access networks and non-3GPP AN may be referred to as non-3GPP access. Also, nodes located in access network_B may be collectively referred to as NG-RAN nodes.

[0024] Furthermore, in the following, access network _A, and / or access network _B, and / or devices included in access network _A, and / or devices included in access network _B may be referred to as access networks or access network devices.

[0025] The core network_A corresponds to an EPC (Evolved Packet Core), which includes, for example, an MME (Mobility Management Entity), an SGW (Serving Gateway), a PGW (Packet Data Network Gateway)-U, a PGW-C, a PCRF (Policy and Charging Rules Function), and an HSS (Home Subscriber Server).

[0026] Furthermore, the core network_B corresponds to a 5G Core Network (5GCN). In the 5GCN, for example, an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), a Policy Control Function (PCF), a Unified Data Management (UDM), etc. are arranged. Here, the 5GCN may be expressed as a 5GC.

[0027] In addition, in the following, core network _A and / or core network _B, devices included in core network _A, and / or devices included in core network _B may be referred to as core networks, core network devices, or devices within the core network.

[0028] The core network (core network _A and / or core network _B) may be an IP mobile communication network operated by a mobile network operator (MNO) that connects the access network (access network _A and / or access network _B) to the PDN and / or DN, or it may be a core network for a mobile network operator that operates and manages the mobile communication system 1, or it may be a core network for a virtual mobile communication operator or virtual mobile communication service provider such as an MVNO (Mobile Virtual Network Operator) or MVNE (Mobile Virtual Network Enabler).

[0029] The core network (core network_A and / or core network_B) and the access network (access network_A and / or access network_B) may differ depending on the mobile communication operator.

[0030] Also, while FIG. 1 illustrates a case where the PDN and the DN are the same, they may be different. The PDN may be a DN (Data Network) that provides communication services to the UE. The DN may be configured as a packet data service network, or may be configured for each service. Furthermore, the PDN may include a connected communication terminal. Therefore, connecting to the PDN may mean connecting to a communication terminal or a server device located in the PDN. Furthermore, transmitting and receiving user data to and from the PDN may mean transmitting and receiving user data to and from a communication terminal or a server device located in the PDN. The PDN may be referred to as the DN, and the DN may be referred to as the PDN.

[0031] In addition, hereinafter, at least a portion of the access network _A, the core network _A, the PDN, the access network _B, the core network _B, and the DN, and / or one or more devices included therein may be referred to as a network or a network device. In other words, when a network and / or a network device sends or receives a message and / or performs a procedure, it means that at least a portion of the access network _A, the core network _A, the PDN, the access network _B, the core network _B, and the DN, and / or one or more devices included therein send or receive a message and / or perform a procedure.

[0032] The UE can also connect to an access network. The UE can also connect to a core network via the access network. The UE can also connect to a PDN or DN via the access network and the core network. That is, the UE can transmit and receive (communicate) user data with the PDN or DN. When transmitting and receiving user data, not only IP (Internet Protocol) communication but also non-IP communication can be used.

[0033] Here, IP communication refers to data communication using IP, and data is transmitted and received using IP packets. An IP packet consists of an IP header and a payload. The payload may include data transmitted and received by devices and functions included in EPS or devices and functions included in 5GS. Non-IP communication refers to data communication that does not use IP, and data is transmitted and received in a format different from the IP packet structure. For example, non-IP communication may be data communication achieved by transmitting and receiving application data without an IP header, or it may be user data transmitted and received by a UE with a different header, such as a MAC header or an Ethernet (registered trademark) frame header, added.

[0034] In addition, access network _A, core network _A, access network _B, core network _B, PDN_A, and DN_A may include devices not shown in Fig. 2. For example, core network _A and / or core network _B and / or PDN_A and / or DN_A may include an AUSF (Authentication Server Function) and an AAA (Authentication, Authorization, and Accounting) server (AAA-S). The AAA server may be located outside the core network.

[0035] Here, the AUSF is a core network device having an authentication function for 3GPP access and non-3GPP access, specifically, a network function unit that receives an authentication request for 3GPP access and / or non-3GPP access from a UE and executes the authentication procedure.

[0036] The AAA server is a device that has authentication, authorization, and accounting functions and is connected to the AUSF directly or indirectly via another network device. The AAA server may be a network device within the core network. The AAA server may not be included in the core network _A and / or core network _B, but may be included in the PLMN. In other words, the AAA server may be a core network device or a device outside the core network. For example, the AAA server may be a server device within the PLMN managed by a third party.

[0037] 2, for the sake of simplicity, each device and function is shown one by one, but multiple similar devices and functions may be configured in the mobile communication system 1. Specifically, the mobile communication system 1 may be configured with multiple devices and functions such as UE_A10, E-UTRAN80, MME40, SGW35, PGW-U30, PGW-C32, PCRF60, HSS50, 5G AN120, AMF140, UPF130, SMF132, PCF160, and / or UDM150.

[0038] [2. Configuration of each device] Next, the configuration of each device (UE, and / or access network device, and / or core network device) used in each embodiment will be described with reference to the drawings. Each device may be configured as physical hardware, as logical (virtual) hardware configured on general-purpose hardware, or as software. Furthermore, at least a part (including all) of the functions of each device may be configured as physical hardware, logical hardware, or software.

[0039] Note that each memory unit (memory unit_A340, memory unit_A440, memory unit_B540, memory unit_A640, memory unit_B740) in each device / function mentioned below is configured with, for example, a semiconductor memory, a solid state drive (SSD), a hard disk drive (HDD), etc. Furthermore, each memory unit can store not only information that was originally set at the time of shipment, but also various information transmitted and received between devices / functions other than the device / function itself (e.g., UE, and / or access network device, and / or core network device, and / or PDN, and / or DN). Furthermore, each memory unit can store identification information, control information, flags, parameters, etc. included in control messages transmitted and received in various communication procedures described below. Furthermore, each memory unit may store this information for each UE. Furthermore, when interworking between 5GS and EPS is performed, each memory unit can store control messages and user data transmitted and received between 5GS and / or devices / functions included in EPS. At this time, not only those transmitted and received via the N26 interface but also those transmitted and received without going through the N26 interface can be stored.

[0040] [2.1. UE Device Configuration] First, an example of the device configuration of UE (User Equipment) will be explained using Figure 3. The UE is composed of a control unit _A300, an antenna 310, a transceiver unit _A320, and a memory unit _A340. The control unit _A300, the transceiver unit _A320, and the memory unit _A340 are connected via a bus. The transceiver unit _A320 is connected to the antenna 310.

[0041] The control unit _A300 is a functional unit that controls the operation and functions of the entire UE.The control unit _A300 realizes various processing in the UE by reading and executing various programs stored in the memory unit _A340 as necessary.

[0042] The transceiver unit _A320 is a functional unit for wireless communication with a base station device (eNB or gNB) in the access network via an antenna. That is, the UE can use the transceiver unit _A320 to transmit and receive user data and / or control information between an access network device, and / or a core network device, and / or a PDN, and / or a DN.

[0043] Explaining in detail with reference to Figure 2, the UE can communicate with a base station device (eNB) in the E-UTRAN via the LTE-Uu interface by using the transceiver unit _A320. The UE can also communicate with a base station device (gNB) in the 5G AN by using the transceiver unit _A320. The UE can also transmit and receive AMF and NAS (Non-Access-Stratum) messages via the N1 interface by using the transceiver unit _A320. However, since the N1 interface is logical, in reality, communication between the UE and the AMF is performed via the 5G AN.

[0044] The memory unit _A340 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the UE.

[0045] [2.2. gNB device configuration] Next, an example of the gNB device configuration will be described using Figure 4. The gNB is composed of a control unit _B500, an antenna 510, a network connection unit _B520, a transceiver unit _B530, and a memory unit _B540. The control unit _B500, the network connection unit _B520, the transceiver unit _B530, and the memory unit _B540 are connected via a bus. The transceiver unit _B530 is connected to the antenna 510.

[0046] The control unit _B500 is a functional unit that controls the operation and functions of the entire gNB. The control unit _B500 realizes various processes in the gNB by reading and executing various programs stored in the memory unit _B540 as necessary.

[0047] The network connection unit _B520 is a functional unit for the gNB to communicate with the AMF and / or UPF. That is, the gNB can send and receive user data and / or control information between the AMF and / or UPF using the network connection unit _B520.

[0048] The transceiver unit _B530 is a functional unit for wireless communication with the UE via the antenna 510. That is, the gNB can transmit and receive user data and / or control information to and from the UE using the transceiver unit _B530.

[0049] 2, a gNB in ​​a 5G AN can communicate with an AMF via an N2 interface by using a network connection unit _B 520, and can communicate with a UPF via an N3 interface, and can communicate with a UE by using a transceiver unit _B 530.

[0050] The memory unit _B540 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the gNB.

[0051] [2.3. AMF device configuration] Next, an example of the AMF device configuration will be explained using Figure 5. The AMF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The AMF may be a node that handles the control plane.

[0052] The control unit _B700 is a functional unit that controls the operation and functions of the entire AMF.The control unit _B700 realizes various processing in the AMF by reading and executing various programs stored in the memory unit _B740 as necessary.

[0053] The network connection unit _B720 is a functional unit for the AMF to connect to a base station device (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF in a 5G AN. In other words, the AMF can use the network connection unit _B720 to send and receive user data and / or control information between a base station device (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF in a 5G AN.

[0054] Explaining in detail with reference to FIG. 2, the AMF in the 5GCN can communicate with a gNB via the N2 interface by using the network connection unit _A620, can communicate with a UDM via the N8 interface, can communicate with an SMF via the N11 interface, and can communicate with a PCF via the N15 interface. The AMF can also send and receive NAS messages with a UE via the N1 interface by using the network connection unit _A620. However, since the N1 interface is logical, communication between the UE and the AMF is actually performed via a 5G AN. Furthermore, if the AMF supports the N26 interface, it can communicate with an MME via the N26 interface by using the network connection unit _A620.

[0055] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the AMF.

[0056] The AMF has functions such as exchanging control messages with the RAN using the N2 interface, exchanging NAS messages with the UE using the N1 interface, encrypting and protecting the integrity of NAS messages, registration management (RM) functions, connection management (CM) functions, reachability management functions, mobility management functions for UEs, etc., transferring SM (Session Management) messages between the UE and the SMF, access authentication (Access Authorization) functions, security anchor functionality (SEA), security context management (SCM), a function to support the N2 interface for the N3IWF (Non-3GPP Interworking Function), a function to support sending and receiving NAS signals with the UE via the N3IWF, and a function to authenticate UEs connected via the N3IWF.

[0057] In addition, registration management manages the RM state for each UE. The RM state may be synchronized between the UE and the AMF. The RM state includes an unregistered state (RM-DEREGISTERED state) and a registered state (RM-REGISTERED state). In the RM-DEREGISTERED state, the UE is not registered with the network, and therefore the UE context in the AMF does not have valid location information or routing information for the UE, and therefore the AMF cannot reach the UE. In the RM-REGISTERED state, the UE is registered with the network, and therefore the UE can receive services that require registration with the network. Note that the RM state may also be expressed as a 5GMM state. In this case, the RM-DEREGISTERED state may be expressed as a 5GMM-DEREGISTERED state, and the RM-REGISTERED state may be expressed as a 5GMM-REGISTERED state.

[0058] In other words, 5GMM-REGISTERED may be a state in which each device has established a 5GMM context or a PDU session context. When each device is 5GMM-REGISTERED, UE_A10 may start transmitting and receiving user data and control messages, or may respond to paging. Furthermore, when each device is 5GMM-REGISTERED, UE_A10 may perform registration procedures other than the registration procedure for initial registration, and / or service request procedures.

[0059] Furthermore, 5GMM-DEREGISTERED may be a state in which each device has not established a 5GMM context, a state in which UE_A10's location information is not known to the network, or a state in which UE_A10 is unreachable from the network. Note that when each device is 5GMM-DEREGISTERED, UE_A10 may initiate a registration procedure or may establish a 5GMM context by performing the registration procedure.

[0060] In addition, connection management manages the CM state for each UE. The CM state may be synchronized between the UE and the AMF. The CM state includes a non-connected state (CM-IDLE state) and a connected state (CM-CONNECTED state). In the CM-IDLE state, the UE is in the RM-REGISTERED state but does not have a NAS signaling connection established with the AMF via the N1 interface. In the CM-IDLE state, the UE does not have an N2 interface connection or an N3 interface connection. On the other hand, in the CM-CONNECTED state, the UE has a NAS signaling connection established with the AMF via the N1 interface. In the CM-CONNECTED state, the UE may have an N2 interface connection and / or an N3 interface connection.

[0061] Furthermore, in connection management, the CM state in 3GPP access and the CM state in non-3GPP access may be managed separately. In this case, the CM state in 3GPP access may include a non-connected state in 3GPP access (CM-IDLE state over 3GPP access) and a connected state in 3GPP access (CM-CONNECTED state over 3GPP access). Furthermore, the CM state in non-3GPP access may include a non-connected state in non-3GPP access (CM-IDLE state over non-3GPP access) and a connected state in non-3GPP access (CM-CONNECTED state over non-3GPP access). Note that the non-connected state may be expressed as an idle mode, and the connected state mode may be expressed as a connected mode.

[0062] The CM state may be expressed as a 5GMM mode. In this case, the unconnected state may be expressed as a 5GMM-IDLE mode, and the connected state may be expressed as a 5GMM-CONNECTED mode. Furthermore, the unconnected state in 3GPP access may be expressed as a 5GMM-IDLE mode over 3GPP access, and the connected state in 3GPP access may be expressed as a 5GMM-CONNECTED mode over 3GPP access. Furthermore, the unconnected state in non-3GPP access may be expressed as 5GMM unconnected mode in non-3GPP access (5GMM-IDLE mode over non-3GPP access), and the connected state in non-3GPP access may be expressed as 5GMM connected mode in non-3GPP access (5GMM-CONNECTED mode over non-3GPP access). Note that the 5GMM unconnected mode may be expressed as idle mode, and the 5GMM connected mode may be expressed as connected mode.

[0063] In addition, one or more AMFs may be placed in the core network B. In addition, the AMF may be an NF that manages one or more NSIs (Network Slice Instances). In addition, the AMF may be a shared CP function (CCNF; Common CPNF (Control Plane Network Function)) shared among multiple NSIs.

[0064] In addition, the N3IWF is a device and / or function located between the non-3GPP access and the 5GCN when the UE connects to the 5GS via the non-3GPP access.

[0065] [2.4. SMF device configuration] Next, an example of the device configuration of SMF132 will be explained using Figure 5. The SMF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The SMF may be a node that handles the control plane.

[0066] The control unit _B700 is a functional unit that controls the operation and functions of the entire SMF.The control unit _B700 realizes various processing in the SMF by reading and executing various programs stored in the memory unit _B740 as necessary.

[0067] The network connection unit _B720 is a functional unit for the SMF to connect with the AMF, and / or UPF, and / or PCF, and / or UDM. In other words, the SMF can send and receive user data and / or control information between the AMF, and / or UPF, and / or PCF, and / or UDM using the network connection unit _B720.

[0068] Explaining in more detail with reference to Figure 2, the SMF in the 5GCN can communicate with the AMF via the N11 interface, with the UPF via the N4 interface, with the PCF via the N7 interface, and with the UDM via the N10 interface by using the network connection unit _A620.

[0069] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the SMF.

[0070] The SMF has session management functions such as establishing, modifying, and releasing PDU sessions, IP address allocation for UEs and its management, UPF selection and control, UPF configuration for routing traffic to the appropriate destination, sending and receiving the SM portion of NAS messages, Downlink Data Notification, providing AN-specific (for each AN) SM information to be sent to the AN via the N2 interface via the AMF, determining the SSC mode (Session and Service Continuity mode) for the session, and roaming functions.

[0071] [2.5. UPF device configuration] Next, an example of the device configuration of the UPF will be explained using Figure 5. The UPF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The UPF may be a node that handles the control plane.

[0072] The control unit _B700 is a functional unit that controls the operation and functions of the entire UPF.The control unit _B700 realizes various processing in the UPF by reading and executing various programs stored in the memory unit _B740 as necessary.

[0073] The network connection unit _B720 is a functional unit for the UPF to connect to a base station device (gNB), and / or SMF, and / or DN within the 5G AN. In other words, the UPF can use the network connection unit _B720 to transmit and receive user data and / or control information between the base station device (gNB), and / or SMF, and / or DN within the 5G AN.

[0074] Explaining in more detail with reference to Figure 2, a UPF in a 5GCN can communicate with a gNB via the N3 interface, with an SMF via the N4 interface, with a DN via the N6 interface, and with other UPFs via the N9 interface by using the network connection unit _A620.

[0075] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the UPF.

[0076] The UPF has functions such as an anchor point for intra-RAT mobility or inter-RAT mobility, an external PDU session point for interconnecting to DNs (i.e., a gateway between DNs and core network_B that forwards user data), packet routing and forwarding functions, an UL CL (Uplink Classifier) ​​function that supports routing of multiple traffic flows to one DN, a branching point function that supports multi-homed PDU sessions, a QoS (Quality of Service) processing function for the user plane, an uplink traffic verification function, downlink packet buffering, and a function to trigger downlink data notifications.

[0077] The UPF may also be a gateway for IP communication and / or non-IP communication. The UPF may also have a function for forwarding IP communication and a function for converting non-IP communication and IP communication. Furthermore, multiple gateways may be gateways that connect the core network_B to a single DN. The UPF may also have connectivity with other NFs and may be connected to each device via other NFs.

[0078] The user plane refers to user data transmitted and received between a UE and a network. The user plane may be transmitted and received using a PDN connection or a PDU session. Furthermore, in the case of EPS, the user plane may be transmitted and received using the LTE-Uu interface, and / or the S1-U interface, and / or the S5 interface, and / or the S8 interface, and / or the SGi interface. Furthermore, in the case of 5GS, the user plane may be transmitted and received via the interface between the UE and the NG RAN, and / or the N3 interface, and / or the N9 interface, and / or the N6 interface. Hereinafter, the user plane may be referred to as the U-Plane.

[0079] Furthermore, the control plane refers to control messages transmitted and received to control UE communications, etc. The control plane may be transmitted and received using a NAS (Non-Access-Stratum) signaling connection between the UE and MME. Furthermore, in the case of EPS, the control plane may be transmitted and received using the LTE-Uu interface and the S1-MME interface. Furthermore, in the case of 5GS, the control plane may be transmitted and received using the interface between the UE and NG RAN and the N2 interface. Hereinafter, the control plane may be referred to as the control plane or the C-Plane.

[0080] Furthermore, the U-Plane (User Plane; UP) may be a communication path for transmitting and receiving user data and may be composed of multiple bearers. Furthermore, the C-Plane (Control Plane; CP) may be a communication path for transmitting and receiving control messages and may be composed of multiple bearers.

[0081] [2.6. Explanation of terms used in this embodiment] Next, other devices, functions, terms, identification information sent, received, stored, and managed by each device, and / or messages will be described.

[0082] A network refers to at least a portion of an access network _B, a core network _B, and a DN. Furthermore, one or more devices included in at least a portion of an access network _B, a core network _B, and a DN may be referred to as a network or a network device. In other words, when a network transmits, receives, and / or processes messages, it may mean that devices within the network (network devices and / or control devices) transmit, receive, receive, and / or process messages. Conversely, when a device within the network transmits, receives, receives, and / or processes messages, it may mean that the network transmits, receives, receives, and / or processes messages.

[0083] In addition, the SM (Session Management) message (also referred to as a NAS (Non-Access-Stratum) SM message) may be a NAS message used in procedures for SM, and may be a control message transmitted and received between UE_A10 and SMF_A230 via AMF_A240. Furthermore, the SM message may include a PDU session establishment request message, a PDU session establishment accept message, a PDU session establishment reject message, a PDU session modification request message, a PDU session modification command message, a PDU session modification complete message, a PDU session modification command reject message, a PDU session modification reject message, a PDU session release request message, a PDU session release reject message, a PDU session release command message, a PDU session release complete message, etc. Furthermore, the procedure for SM or the SM procedure may include a PDU session establishment procedure, a PDU session modification procedure, and a UE-requested PDU session release procedure.Each procedure may be initiated from the UE or from the NW.

[0084] Furthermore, an MM (Mobility management) message (also referred to as an NAS MM message) may be an NAS message used in procedures for MM, and may be a control message transmitted and received between UE_A10 and AMF_A240. Furthermore, the MM message may include a registration request message, a registration accept message, a registration reject message, a de-registration request message, a de-registration accept message, a configuration update command message, a configuration update complete message, a service request message, a service accept message, a service reject message, a notification message, a notification response message, etc. In addition, the procedures for MM or MM procedures may include a registration procedure, a de-registration procedure, a generic UE configuration update procedure, an authentication and authorization procedure, a service request procedure, a paging procedure, and a notification procedure.

[0085] In addition, the 5GS (5G System) service may be a connection service provided using the core network_B190. Furthermore, the 5GS service may be a service different from the EPS service or may be a service similar to the EPS service.

[0086] In addition, non-5GS services may be services other than 5GS services, and may include EPS services and / or non-EPS services.

[0087] Also, the PDN (Packet Data Network) type indicates the type of PDN connection, and can be IPv4, IPv6, IPv4v6, or non-IP. If IPv4 is specified, it indicates that data will be sent and received using IPv4. If IPv6 is specified, it indicates that data will be sent and received using IPv6. If IPv4v6 is specified, it indicates that data will be sent and received using either IPv4 or IPv6. If non-IP is specified, it indicates that communication will not be via IP, but via a communication method other than IP.

[0088] There are two types of access types: 3GPP access and non-3GPP access. Here, information indicating the access type may be configured as an access type information element (IE), and may be, for example, identification information indicating the access type used in signaling between the UE and the core network or in transmitting and receiving user data.

[0089] Furthermore, the term "access technology" refers to the type of radio access technology for 3GPP access, and may include NG-RAN, E-UTRAN, UTRAN, GERAN, etc. The access technology is also referred to as "access technology." The access technology may be identified by an access network identifier. Furthermore, the access network identifier may be information capable of identifying the access technology and the operation mode of the access technology.

[0090] Furthermore, a PDU (Protocol Data Unit / Packet Data Unit) session can be defined as an association between a DN that provides a PDU connectivity service and a UE, but it may also be connectivity established between a UE and an external gateway. In 5GS, a UE can transmit and receive user data to and from a DN by establishing a PDU session via an access network _B and a core network _B. Here, this external gateway may be a UPF, SCEF, or the like. The UE can transmit and receive user data to and from a device such as an application server located in the DN using the PDU session.

[0091] Each device (UE, and / or access network device, and / or core network device) may associate one or more pieces of identification information with a PDU session and manage them. These pieces of identification information may include one or more of the following: DNN, QoS rule, PDU session type, application identification information, NSI identification information, access network identification information, and SSC mode, or may further include other information. Furthermore, when multiple PDU sessions are established, the identification information associated with the PDU sessions may be the same or different.

[0092] Furthermore, the DNN (Data Network Name) may be identification information that identifies the core network and / or an external network such as a DN. Furthermore, the DNN can also be used as information for selecting a gateway such as PGW_A30 / UPF_A235 that connects the core network _B190. Furthermore, the DNN may be equivalent to an APN (Access Point Name).

[0093] Furthermore, the PDU (Protocol Data Unit / Packet Data Unit) session type indicates the type of PDU session, and can be IPv4, IPv6, Ethernet, or Unstructured. If IPv4 is specified, it indicates that data will be sent and received using IPv4. If IPv6 is specified, it indicates that data will be sent and received using IPv6. If Ethernet is specified, it indicates that Ethernet frames will be sent and received. Furthermore, Ethernet may indicate that communication using IP is not performed. If Unstructured is specified, it indicates that data will be sent and received to an application server or the like in the DN using Point-to-Point (P2P) tunneling technology. As the P2P tunneling technology, for example, UDP / IP encapsulation technology may be used. In addition to the above, the PDU session type may also include IP. IP can be specified if the UE is capable of using both IPv4 and IPv6.

[0094] Also, a PLMN (Public Land Mobile Network) is a communication network that provides mobile radio communication services. A PLMN is a network managed by an operator, which is a (mobile) communications carrier, and the operator can be identified by a PLMN ID. In this document, PLMN may refer to a PLMN ID. A PLMN that matches the MCC (Mobile Country Code) and MNC (Mobile Network Code) of a UE's IMSI (International Mobile Subscriber Identity) may be a Home PLMN (HPLMN). A Visited PLMN (VPLMN) may be a PLMN different from the HPLMN or the HEPLMN (Home Equivalent PLMN). PLMN may also refer to a core network.

[0095] Furthermore, the UE may store an Equivalent HPLMN list in the Universal Subscriber Identity Module (USIM) to identify one or more Equivalent HPLMNs (EHPLMNs). A PLMN different from the HPLMN and / or EHPLMN may be a Visited PLMN (VPLMN or vPLMN).

[0096] A PLMN to which a UE has successfully registered may be a Registered PLMN (RPLMN). Each device may receive, maintain, and / or store an Equivalent PLMN list from the RPLMN to identify one or more Equivalent PLMNs (EPLMNs) that can be used equivalently to the RPLMN in the UE's PLMN selection.

[0097] The current PLMN may be the PLMN requested by the UE, and / or the PLMN selected by the UE, and / or the RPLMN, and / or the PLMN allowed by the network, and / or the PLMN to which the core network device sending or receiving the message belongs.

[0098] The requested PLMN refers to the network to which the UE sends a message when the UE sends the message. Specifically, it may be the PLMN selected by the UE when the UE sends the message. The requested PLMN is the PLMN requested by the UE, and may be the current PLMN. When the UE is in a registered state, the requested PLMN may be the registered PLMN.

[0099] Furthermore, the SOR (Steering of Roaming) transparent container information element may include information for the HPLMN and / or VPLMN to indicate the optimal roaming destination network to the roaming UE. Specifically, the SOR transparent container information element may include a list of preferred PLMN / access technology combinations.

[0100] In addition, the SOR transparent container information element and / or list of preferred PLMN / access technology combinations may be included in a "Secured packet" encrypted by the PLMN (HPLMN) using security functions, and may also be referred to as a "Secured packet."

[0101] In addition, the Steering of Roaming application function (SOR-AF), which is one of the entities in the core network, may provide information including a list of preferred PLMN / access technology combinations to the UDM, or the AMF may refer to the information including the list of preferred PLMN / access technology combinations provided to the UDM, generate a SOR transparent container information element based on this information, and send it to the UE.

[0102] Here, the list of preferred PLMN / access technology combinations may be a list consisting of combinations of PLMNs (preferred PLMNs) and access technologies, and each combination may be arranged in descending order of priority.

[0103] Furthermore, for example, when a UE switches networks due to mobility or selects a PLMN in automatic mode when powering on at a roaming destination, the highest priority, usable, and allowable combination of PLMN and access technology may be selected.

[0104] A network slice (NS) is a logical network that provides specific network capabilities and network characteristics. UEs and / or networks can support network slices (NW slices; NS) in 5GS. A network slice may also be simply referred to as a slice.

[0105] A network slice instance (NSI) is composed of an instance (entity) of a network function (NF) and a set of required resources, forming a deployed network slice. Here, an NF is a processing function in a network, adopted or defined by 3GPP. An NSI is an entity of an NS, of which one or more are configured within a core network_B. An NSI may also be composed of a virtual network function (NF) generated using a network slice template (NST).

[0106] Here, an NST is a logical representation of one or more NFs associated with resource requirements for providing the required communication services and capabilities. In other words, an NSI may be a collection of multiple NFs within the core network_B190. An NSI may also be a logical network configured to separate user data delivered by services, etc. An NS may be configured with one or more NFs. The NFs configured in an NS may or may not be devices shared with other NSs.

[0107] A UE and / or a device in the network can be assigned to one or more NSs based on registration information such as an NSSAI, an S-NSSAI, an UE usage type, an NSI ID, or one or more NSI IDs, and / or an APN. The UE usage type is a parameter value included in the UE registration information and used to identify the NSI. The UE usage type may be stored in the HSS. The AMF may select the SMF 132 and the UPF based on the UE usage type.

[0108] Furthermore, S-NSSAI (Single Network Slice Selection Assistance Information) is information for identifying an NS. The S-NSSAI may consist of only an SST (Slice / Service type) or may consist of both an SST and an SD (Slice Differentiator). Here, the SST is information indicating the expected behavior of the NS in terms of functions and services. The SD may be information that interpolates the SST when selecting one NSI from multiple NSIs indicated by the SST. The S-NSSAI may be information specific to each PLMN, or may be standard information common among PLMNs. The network may store one or more S-NSSAIs as default S-NSSAIs in the registration information of the UE. Note that when the S-NSSAI is the default S-NSSAI, if the UE does not send a valid S-NSSAI to the network in a registration request message, the network may provide an NS related to the UE.

[0109] Furthermore, the S-NSSAI transmitted and received between the UE and the NW may be expressed as an S-NSSAI IE (Information element). Furthermore, the S-NSSAI IE transmitted and received between the UE and the NW may be configured with an S-NSSAI configured with an SST and / or SD of the registered PLMN, and / or an SST and / or SD indicating the S-NSSAI of the HPLMN to which the S-NSSAI is mapped. One or more S-NSSAIs stored in the UE and / or NW may be configured with an SST and / or SD, or may be configured with an S-NSSAI configured with an SST and / or SD, and / or an SST and / or SD indicating the S-NSSAI of the HPLMN to which the S-NSSAI is mapped.

[0110] Also, NSSAI (Network Slice Selection Assistance Information) is a collection of S-NSSAIs. Each S-NSSAI included in the NSSAI is information that assists the access network or core network in selecting an NSSAI. The UE may store an NSSAI allowed by the network for each PLMN. The NSSAI may also be information used to select an AMF. The UE may apply each NSSAI (allowed NSSAI, and / or configured NSSAI, and / or rejected NSSAI, and / or pending NSSAI, and / or first NSSAI) to the PLMN and the EPLMN.

[0111] A mapped S-NSSAI is an S-NSSAI of an HPLMN that is mapped to an S-NSSAI of a registered PLMN in a roaming scenario. The UE may store one or more mapped S-NSSAIs that are mapped to the configured NSSAI and the S-NSSAI included in the allowed NSSAI for each access type. Furthermore, the UE may store one or more mapped S-NSSAIs for the first NSSAI, the rejected NSSAI, and / or the S-NSSAI included in the pending NSSAI.

[0112] The Network Slice-Specific Authentication and Authorization (NSSAA) function is a function for realizing network slice-specific authentication and authorization. Network slice-specific authentication and authorization allows UE authentication and authorization to be performed outside the core network, such as by a third party. PLMNs and network devices with NSSAA functionality can perform NSSAA procedures for a certain S-NSSAI based on the UE's registration information. Furthermore, UEs with NSSAA functionality can manage, store, and send / receive pending NSSAIs and third rejected NSSAIs. In this document, NSSAA may be referred to as the network slice-specific authentication and authorization procedure or the authentication and authorization procedure.

[0113] The S-NSSAI requiring an NSSAA is an S-NSSAI requiring an NSSAA that is managed by a core network and / or a core network device. Furthermore, the S-NSSAI requiring an NSSAA may be an S-NSSAI other than the HPLMN, where the S-NSSAI requiring an NSSAA that is managed by a core network and / or a core network device becomes a mapped S-NSSAI.

[0114] The core network and / or core network device may store an S-NSSAI requiring an NSSAA by associating the S-NSSAI with information indicating whether an NSSAA is required. The core network and / or core network device may further store an S-NSSAI requiring an NSSAA in association with information indicating whether an NSSAA has been completed, or information indicating that the NSSAA has been completed and is permitted or successful. The core network and / or core network device may manage an S-NSSAI requiring an NSSAA as information unrelated to the access network.

[0115] Also, a configured NSSAI is an NSSAI provided and stored in the UE. The UE may store a configured NSSAI for each PLMN. The UE may store a configured NSSAI in association with a PLMN. In this document, a configured NSSAI associated with a PLMN may be expressed as a configured NSSAI for the PLMN, a configured NSSAI of the PLMN, a configured NSSAI for the PLMN, or a configured NSSAI associated with the PLMN. Also, a UE may not be associated with a PLMN and may store a configured NSSAI that is valid for all PLMNs, and such a configured NSSAI may be referred to as a "default configured NSSAI."

[0116] The configured NSSAI may be associated with multiple PLMNs, which may be EPLMNs.

[0117] The configured NSSAI may be information configured by the network (or PLMN). The S-NSSAI included in the configured NSSAI may be expressed as the configured S-NSSAI. The configured S-NSSAI may be configured to include the S-NSSAI and the mapped S-NSSAI. Alternatively, the S-NSSAI of the PLMN may be expressed as the "configured S-NSSAI", and the S-NSSAI to which the configured S-NSSAI is mapped to the HPLMN may be expressed as the "mapped S-NSSAI to the configured NSSAI for the PLMN".

[0118] Furthermore, the requested NSSAI is an NSSAI provided by the UE to the network during the registration procedure. In the registration procedure, the S-NSSAI included in the requested NSSAI sent by the UE may be the S-NSSAI included in the allowed NSSAI or configured NSSAI stored by the UE. In the PDU session establishment procedure, the S-NSSAI included in the requested NSSAI sent by the UE may be the S-NSSAI included in the allowed NSSAI stored by the UE.

[0119] The requested NSSAI may be information indicating a network slice requested by the UE. The S-NSSAI included in the requested NSSAI may be expressed as a requested S-NSSAI. For example, the requested NSSAI is transmitted in a NAS message, such as a registration request message or a PDU session establishment request message, transmitted from the UE to the network, or in a Radio Resource Control (RRC) message including a Non-Access-Stratum (NAS) message.

[0120] Also, the allowed NSSAI is information indicating one or more network slices to which the UE is permitted. In other words, the allowed NSSAI is information identifying a network slice to which the network permits the UE to connect.

[0121] The UE and / or NW may store and manage the allowed NSSAI for each access (3GPP access or non-3GPP access) as information of the UE. The UE and / or NW may further manage the allowed NSSAI in association with a registration area.

[0122] Furthermore, the UE and / or NW may store and manage an allowed NSSAI associated with a PLMN as information of the UE. The allowed NSSAI may be associated with multiple PLMNs, and these multiple PLMNs may be EPLMNs.

[0123] In this document, an allowed NSSAI associated with a PLMN and an access type may be expressed as an allowed NSSAI for the PLMN and access type, or an allowed NSSAI for the access type of the PLMN. An S-NSSAI included in an allowed NSSAI may be expressed as an allowed S-NSSAI. An allowed S-NSSAI may be configured to include an S-NSSAI and a mapped S-NSSAI.

[0124] Furthermore, the rejected NSSAI is information indicating one or more network slices to which the UE is not permitted. In other words, the rejected NSSAI is information identifying a network slice to which the network does not permit the UE to connect. The rejected NSSAI may be information including one or more combinations of an S-NSSAI and a rejection reason value.

[0125] Here, the rejection reason value is information indicating the reason why the network rejects the corresponding S-NSSAI. The UE and the network may store and manage the rejected NSSAI appropriately based on the rejection reason value associated with each S-NSSAI.

[0126] Furthermore, the rejected NSSAI may be included in an NAS message transmitted from the network to the UE, such as a registration accept message, a configuration update command, or a registration reject message, or in an RRC message including an NAS message. The S-NSSAI included in the rejected NSSAI may be expressed as the rejected S-NSSAI.

[0127] The rejected NSSAI may be any one of the first to third rejected NSSAIs, the pending NSSAI, and the first NSSAI, or a combination of these. An S-NSSAI included in the rejected NSSAI may be expressed as a rejected S-NSSAI. The rejected S-NSSAI may be configured to include an S-NSSAI and a mapped S-NSSAI.

[0128] The UE and / or NW may store and manage the rejected NSSAI associated with the PLMN as information of the UE. The rejected NSSAI may be associated with multiple PLMNs, and these multiple PLMNs may be EPLMNs.

[0129] In this document, a rejected NSSAI associated with a PLMN may be referred to as a rejected NSSAI for the PLMN or a rejected NSSAI of the PLMN. The UE and / or NW may further store the second rejected NSSAI and / or the second rejected S-NSSAI in association with a registration area. The UE and / or NW may store the second rejected NSSAI and / or the second rejected S-NSSAI in association with an access type and / or a registration area.

[0130] Here, the first rejected NSSAI is a set of one or more S-NSSAIs that are unavailable in the current PLMN among the S-NSSAIs included in the requested NSSAI by the UE. The first rejected NSSAI may be a 5GS rejected NSSAI for the current PLMN, a rejected S-NSSAI for the current PLMN, or an S-NSSAI included in the rejected NSSAI for the current PLMN. The first rejected NSSAI may be a rejected NSSAI stored by the UE or the NW, or may be a rejected NSSAI transmitted from the NW to the UE. If the first rejected NSSAI is a rejected NSSAI transmitted from the NW to the UE, the first rejected NSSAI may be information including one or more combinations of an S-NSSAI and a reason value. The rejection reason value at this time may be "S-NSSAI not available in the current PLMN" or may be information indicating that the S-NSSAI associated with the rejection reason value is not available in the current PLMN or SNPN. The S-NSSAI included in the first rejected NSSAI may be expressed as the first rejected S-NSSAI.

[0131] The first rejected NSSAI may apply to the entire registered PLMN. The UE and / or NW may treat the first rejected NSSAI and the S-NSSAI included in the first rejected NSSAI as information independent of the access type. That is, the first rejected NSSAI may be information valid for both 3GPP access and non-3GPP access.

[0132] The UE may delete the first rejected NSSAI from its storage when it transitions to an unregistered state in both 3GPP access and non-3GPP access with respect to the current PLMN. In other words, when the UE transitions to an unregistered state with respect to the current PLMN via one access, or when it successfully registers to a new PLMN via one access, or when it fails to register to the new PLMN via one access and transitions to an unregistered state, and the UE is not registered via the other access (unregistered state), the UE deletes the first rejected NSSAI. In other words, when the UE transitions to an unregistered state with respect to the current PLMN via one access, and the UE is registered (registered state) with the current PLMN via the other access, the UE does not need to delete the first rejected NSSAI.

[0133] The second rejected NSSAI is a set of one or more S-NSSAIs that are unavailable in the current registration area among the S-NSSAIs included in the requested NSSAI by the UE. The second rejected NSSAI may be a 5GS rejected NSSAI for the current registration area. The second rejected NSSAI may be a rejected NSSAI stored by the UE or the NW, or may be a rejected NSSAI transmitted from the NW to the UE. If the second rejected NSSAI is a rejected NSSAI transmitted from the NW to the UE, the second rejected NSSAI may be information including one or more combinations of an S-NSSAI and a reason value. In this case, the rejection reason value may be "S-NSSAI not available in the current registration area" or may be information indicating that the S-NSSAI associated with the reason value is unavailable in the current registration area. An S-NSSAI included in the second rejected NSSAI may be expressed as the second rejected S-NSSAI.

[0134] The second rejected NSSAI may be valid within the current registration area and may apply to the current registration area. The UE and / or NW may treat the second rejected NSSAI and the S-NSSAI included in the second rejected NSSAI as information for each access type. That is, the second rejected NSSAI may be information valid for each of 3GPP access and non-3GPP access. That is, once the UE transitions to an unregistered state for an access, the UE may delete the second rejected NSSAI associated with that access from its memory.

[0135] The third rejected NSSAI is a set of one or more S-NSSAIs that require an NSSAA and for which the NSSAA for that S-NSSAI has failed or been revoked. The third rejected NSSAI may be an NSSAI stored by the UE and / or the NW, or may be an NSSAI transmitted and received between the NW and the UE. When the third rejected NSSAI is transmitted from the NW to the UE, the third rejected NSSAI may be information including one or more combinations of an S-NSSAI and a rejection reason value. In this case, the rejection reason value may be "S-NSSAI not available due to the failed or revoked NSSAA" or may be information indicating that the NSSAA for the S-NSSAI associated with the rejection reason value has failed or been revoked. The S-NSSAI included in the third rejected NSSAI may be expressed as the third rejected S-NSSAI.

[0136] The third rejected NSSAI may apply to the entire registered PLMN, may apply to the registered PLMN and / or the EPLMN, or may apply to all PLMNs. Applying the third rejected NSSAI to all PLMNs may mean that the third rejected NSSAI is not associated with a PLMN, or may mean that the third rejected NSSAI is associated with a HPLMN.

[0137] Furthermore, the UE and / or NW may treat the third rejected NSSAI and the third rejected S-NSSAI as information independent of the access type. That is, the third rejected NSSAI may be information valid for 3GPP access and non-3GPP access. The third rejected NSSAI may be an NSSAI different from the rejected NSSAI. The third rejected NSSAI may be the first rejected NSSAI. The third rejected NSSAI may be a 5GS rejected NSSAI for the failed or revoked NSSAA, a rejected S-NSSAI for the failed or revoked NSSAA, or an S-NSSAI included in the rejected NSSAI for the failed or revoked NSSAA.

[0138] The third rejected NSSAI identifies a slice that the UE rejected due to an NSSAA failure or revocation from the core network. Specifically, while the UE stores the third rejected NSSAI, it does not initiate a registration request procedure for the S-NSSAI included in the third rejected NSSAI. The third rejected NSSAI may be identification information including one or more S-NSSAIs received from the core network in association with a rejection reason value indicating an NSSAA failure. The third rejected NSSAI is information independent of the access type. Specifically, when the UE stores the third rejected NSSAI, the UE may not attempt to send a registration request message including the S-NSSAI included in the third rejected NSSAI to both 3GPP access and non-3GPP access. Alternatively, the UE may send a registration request message including the S-NSSAI included in the third rejected NSSAI based on a UE policy. Alternatively, the UE may delete the third rejected NSSAI based on the UE policy and transition to a state in which it can transmit a registration request message including an S-NSSAI included in the third rejected NSSAI. In other words, when the UE transmits a registration request message including an S-NSSAI included in the third rejected NSSAI based on the UE policy, the UE may delete the S-NSSAI from the third rejected NSSAI.

[0139] The first NSSAI is information including one or more S-NSSAIs for which the maximum number of UEs per network slice has been reached. The first NSSAI may be a rejected NSSAI, an allowed NSSAI, or a pending NSSAI. The first NSSAI may be an NSSAI stored by the UE and / or the NW, or an NSSAI transmitted from the NW to the UE.

[0140] When the first NSSAI is transmitted from the NW to the UE, the first NSSAI may be information including one or more pieces of information including at least one of an S-NSSAI, a mapped S-NSSAI, a rejection reason value, a back-off timer value, and information indicating the validity range of the back-off timer value. In this case, the rejection reason value may be "the S-NSSAI has reached the maximum number of UEs per network slice" or may be information indicating that the maximum number of UEs that can be allowed for the S-NSSAI associated with the rejection reason value has been reached. Here, the rejection reason value may be the rejection reason value included in the rejected NSSAI, flag information, or a 5GMM cause. Furthermore, in this case, the back-off timer value may be information indicating a period during which the UE is prohibited from transmitting MM messages and SM messages using the S-NSSAI related to the corresponding S-NSSAI or mapped S-NSSAI.

[0141] Furthermore, the information indicating the validity range of the backoff timer value may be information indicating whether the backoff timer value applies to the current PLMN (Public Land Mobile Network), applies to all PLMNs, or is valid in the current registration area.

[0142] The first NSSAI may apply to the entire registered PLMN, may be valid for all PLMNs, may apply, may be valid within a registration area, may apply to the registered PLMN and the EPLMN, or may apply to one or more PLMNs to which a TAI included in the TA list (TAI list or registration area) belongs. The first NSSAI applying to all PLMNs may mean that the first NSSAI is not associated with a PLMN, or may mean that the first NSSAI is associated with a HPLMN.

[0143] If the first NSSAI is valid for the entire registered PLMN, or applies to all PLMNs, or applies to the registered PLMN and / or EPLMN, the UE and / or NW may treat the first NSSAI and the S-NSSAI included in the first NSSAI as information independent of the access type.If the first NSSAI is valid within the registration area, or applies to one or more PLMNs to which the TAIs included in the TA list (TAI list or registration area) belong, the UE and / or NW may treat the first NSSAI and the S-NSSAI included in the first NSSAI as information specific to the access type.

[0144] The first NSSAI may be an allowed NSSAI, a rejected NSSAI, a pending NSSAI, or information different from these.

[0145] A pending NSSAI is a set of one or more S-NSSAIs that are pending and / or unavailable for use by the UE. A pending NSSAI may be a set of S-NSSAIs for which the network requires network slice specific authentication and for which network slice specific authentication has not been completed. A pending NSSAI may be a pending NSSAI for 5GS. A pending NSSAI may be an NSSAI stored by the UE and / or NW, or an NSSAI transmitted and received between the NW and the UE.

[0146] When the pending NSSAI is an NSSAI transmitted from the NW to the UE, the pending NSSAI may be information including one or more combinations of an S-NSSAI and a rejection reason value. In this case, the rejection reason value may be "NSSAA is pending for the S-NSSAI" and may be information indicating that the S-NSSAI associated with the rejection reason value is prohibited or pending from being used by the UE until the NSSAA for that S-NSSAI is completed.

[0147] If the pending NSSAI is an NSSAI transmitted from the NW to the UE, the pending NSSAI may be a set of combinations of the S-NSSAI and the mapped S-NSSAI.

[0148] The pending NSSAI may apply to the entire registered PLMN, to the registered PLMN and one or more EPLMNs of the registered PLMN, or to all PLMNs. A pending NSSAI that applies to all PLMNs may mean that the pending NSSAI is not associated with a PLMN, or may mean that the pending NSSAI is associated with a HPLMN.

[0149] The UE and / or NW may treat the S-NSSAI included in the pending NSSAI as information independent of the access type. That is, the pending NSSAI may be information valid for 3GPP access and non-3GPP access. The pending NSSAI may be an NSSAI different from the rejected NSSAI. The pending NSSAI may be the first rejected NSSAI.

[0150] The pending NSSAI is an NSSAI consisting of one or more S-NSSAIs that identify slices for which the UE has pending a procedure. Specifically, while the UE stores the pending NSSAI, it does not initiate a registration request procedure for the S-NSSAI included in the pending NSSAI. In other words, the UE does not use the S-NSSAI included in the pending NSSAI during the registration procedure until the NSSAA for the S-NSSAI included in the pending NSSAI is completed. The pending NSSAI is information that is independent of the access type. Specifically, when the UE stores the pending NSSAI, it does not attempt to send a registration request message including the S-NSSAI included in the pending NSSAI to both 3GPP access and non-3GPP access.

[0151] A tracking area is a single or multiple ranges managed by the core network that can be represented by the location information of UE_A10. A tracking area may be composed of multiple cells. Furthermore, a tracking area may be an area in which control messages such as paging are broadcast, or an area in which UE_A10 can move without performing a handover procedure. Furthermore, a tracking area may be a routing area, a location area, or anything similar. Hereinafter, a tracking area may be a TA (Tracking Area). A tracking area may be identified by a TAI (Tracking Area Identity) consisting of a TAC (Tracking area code) and a PLMN.

[0152] A registration area is a collection of one or more TAs assigned to a UE by the AMF. Note that while UE_A10 is moving within one or more TAs included in the registration area, it may be able to move without sending or receiving signals for tracking area update. In other words, a registration area may be a group of information indicating areas in which UE_A10 can move without performing a tracking area update procedure. A registration area may be identified by a TAI list consisting of one or more TAIs.

[0153] The TAIs included in the TAI list may belong to one PLMN or multiple PLMNs. If multiple TAIs included in the TAI list belong to different PLMNs, those PLMNs may be EPLMNs.

[0154] The UE ID is information for identifying a UE. Specifically, for example, the UE ID may be a SUCI (Subscription Concealed Identifier), a SUPI (Subscription Permanent Identifier), a GUTI (Globally Unique Temporary Identifier), an IMEI (International Mobile Subscriber Identity), an IMEISV (IMEI Software Version), or a TMSI (Temporary Mobile Subscriber Identity). Alternatively, the UE ID may be other information set in an application or a network. Furthermore, the UE ID may be information for identifying a user.

[0155] A disaster condition in a PLMN may be a condition in which a network (PLMN) is unable to provide communication services to users due to a natural disaster or human error. A PLMN may apply a disaster condition when a disaster condition occurs, and the disaster condition may apply to the entire PLMN or to specific areas or functions of the PLMN.

[0156] In this paper, the PLMN that applies the disaster state is also referred to as "PLMN D," and the PLMN that is not in the disaster state is also referred to as "PLMN A."

[0157] Disaster roaming may refer to a UE registered or connected to a PLMN in which a disaster state is applied, moving (roaming) to another network (PLMN) to continue using communication services. Disaster roaming may be performed based on the application of a disaster state by the network. The selection of the destination PLMN may also be based on information received, stored, and managed by the UE from the network.

[0158] A forbidden PLMN list (or list of "forbidden PLMN(s)") is a list that manages PLMNs for which connection (access) and / or registration is prohibited, and may be a list including zero or more PLMN IDs. Here, the forbidden PLMN list may be a list that is managed internally by the UE. More specifically, when the UE performs a registration procedure, the UE may add the PLMN ID of the core network to the forbidden PLMN list based on receiving a registration rejection message from the core network.

[0159] In addition, multiple forbidden PLMN lists may be managed within the UE for each access type, and for example, two lists may be managed: a forbidden PLMN list for 3GPP access and a forbidden PLMN list for non-3GPP access.

[0160] The forbidden PLMN list may also be stored and managed in the UE, for example, in a Universal Subscriber Identity Module (USIM) or SIM.

[0161] If the UE does not store a valid PLMN ID other than the prohibited PLMN list when performing disaster roaming, the UE may perform a registration procedure for a PLMN ID included in the prohibited PLMN list. In this case, the registration request message may further include information indicating disaster roaming.

[0162] Furthermore, the UE may manage a list for managing PLMNs for which a disaster state has been applied or released, which is also referred to as a forbidden PLMN list for a disaster state in this document.

[0163] Here, the forbidden PLMN list for the disaster state may be configured as a list including zero or more PLMN IDs for which the disaster state has been applied and which the UE has been notified of and / or recognized by the network. More specifically, for example, when the UE receives identification information indicating the PLMN ID for which the disaster state has been applied (third identification information described below), the UE may add the PLMN ID indicated by the identification information to the forbidden PLMN list for the disaster state. Conversely, when the UE receives identification information indicating the PLMN ID for which the disaster state has been lifted (fourth identification information described below), the UE may delete the PLMN ID indicated by the identification information from the forbidden PLMN list for the disaster state.

[0164] Furthermore, the forbidden PLMN list for disaster conditions may be a list that manages PLMNs (PLMN IDs) for which connection (access) and / or registration is prohibited, similar to the forbidden PLMN list described above, and may include zero or more PLMN IDs, and may be managed for each access type.

[0165] In addition, the aforementioned forbidden PLMN list and / or PLMN list for disaster conditions may be deleted by powering on / off or removing and inserting the USIM.

[0166] Furthermore, the forbidden PLMN list for a disaster state may be a list including one or more PLMN IDs. In other words, the forbidden PLMN list for a disaster state may be a set including one or more PLMN IDs. Here, the PLMN ID may be information identifying a PLMN to which a disaster state applies. In other words, the PLMN ID may be the PLMN ID of a PLMN to which a disaster state applies.

[0167] Furthermore, the forbidden PLMN list for a disaster condition may be a list that manages PLMNs (PLMN IDs) for which connection (access) and / or registration is prohibited while the PLMN is in a disaster condition. In other words, the forbidden PLMN list for a disaster condition may be a list that manages PLMNs (PLMN IDs) for which connection (access) and / or registration is prohibited due to a disaster condition.

[0168] Furthermore, the forbidden PLMN list for disaster conditions may be a list managed by the UE. Furthermore, the forbidden PLMN list for disaster conditions may be a list shared between the UE and the core network.

[0169] Furthermore, when the UE receives identification information (third identification information described below) indicating that a disaster state has been applied, the UE may add the current PLMN to the forbidden PLMN list for the disaster state. More specifically, when the UE receives identification information (third identification information described below) indicating that a disaster state has been applied, the UE may add a PLMN ID indicating the current PLMN to the forbidden PLMN list for the disaster state.

[0170] Conversely, when identification information (fourth identification information described later) indicating that the disaster state of PLMN_A has been lifted is received, PLMN_A may be deleted from the list of prohibited PLMNs in the disaster state. More specifically, when identification information (fourth identification information described later) indicating that the disaster state of PLMN_A has been lifted is received, the PLMN ID indicating PLMN_A may be deleted from the list of prohibited PLMNs in the disaster state. Here, PLMN_A may be a PLMN that was previously registered. Furthermore, PLMN_A may be a Home PLMN (HPLMN).

[0171] In addition, the network may have a "disaster roaming PLMN list" or a "disaster roaming PLMN and area list" as a list for managing PLMNs and / or specific areas of PLMNs to which disaster roaming is applied, and these lists may be provided to the UE. Furthermore, the UE that receives these lists may store them and manage them in the same way as the forbidden PLMN list for disaster roaming described above. In this document, the "disaster roaming PLMN list" or "disaster roaming PLMN and area list" that is provided by the network, stored by the UE, and further subject to management such as addition or deletion of PLMN IDs or area information may also be referred to as a forbidden PLMN list during disaster roaming.

[0172] SOR is an abbreviation for Steering of Roaming, and refers to a method or technology for encouraging a UE to roam to a network that is a preferred roaming destination (or a recommended roaming destination) indicated by an HPLMN.

[0173] SOR-CMCI (Steering of roaming connected mode control information) is HPLMN information for controlling the timing of transition from 5GMM connected mode to 5GMM disconnected mode in order for the UE to perform SOR. SOR-CMCI may be included in SOR information and / or an SOR transparent container, or may be included in other information elements and transmitted / received.

[0174] The SOR-CMCI may include criteria information and a first timer value. Furthermore, the criteria information and the first timer value may be associated with each other.

[0175] Here, the criteria information may include criteria belonging to a PDU session, and / or criteria relating to a service type, and / or criteria belonging to all types.

[0176] Furthermore, the criteria belonging to a PDU session may be criteria information for identifying the corresponding PDU session. Specifically, the criteria belonging to a PDU session may be criteria information including one or more of S-NSSAI_A, DNN_A, 5QI_A, access type, PDU session type, and PDU session ID_A.

[0177] Furthermore, the criteria regarding the service type may be criteria information for identifying the corresponding service, specifically, the criteria regarding the service type may be criteria information including one or more of IMS registration related signaling, MMTEL voice call, MMTEL video call, MO SMS over NAS, or MO SMSoIP.

[0178] Furthermore, the criteria belonging to all types may be criteria information that matches in any state.

[0179] Furthermore, the SOR-CMCI may include a plurality of pieces of criteria information. When a plurality of pieces of criteria information are included in the SOR-CMCI, the SOR-CMCI may include a plurality of first timer values. In this case, the criteria information and the first timer values ​​may be associated one-to-one.

[0180] In other words, if multiple PDU sessions are established, the SOR-CMCI may include multiple criteria information and multiple first timer values. Furthermore, if multiple services are running, the SOR-CMCI may also include multiple criteria information and multiple first timer values.

[0181] Furthermore, each piece of criteria information may also include a priority level. In other words, each piece of criteria information may also include information indicating the priority level of the criteria information.

[0182] Conversely, the SOR-CMCI may include only one piece of criteria information. When only one piece of criteria information is included in the SOR-CMCI, the SOR-CMCI may include one first timer value. In this case, the criteria information and the first timer value may also be associated one-to-one. Furthermore, in this case, the SOR information and / or SOR transparent container information element may include one or more SOR-CMCIs.

[0183] In other words, if multiple PDU sessions are established, the SOR information and / or the SOR transparent container may include multiple SOR-CMCIs. Furthermore, if multiple services are running, the SOR information and / or the SOR transparent container information element may also include multiple SOR-CMCIs.

[0184] Furthermore, each SOR-CMCI may also include a priority, in other words, each SOR-CMCI may also include information indicating the priority of the SOR-CMCI.

[0185] The SOR-CMCI may be determined based on operator policy and may be information sent from the UDM to the UE.

[0186] The SOR information (Steering of roaming information) may be information of the SOR configured with information protected by the HPLMN. The Steering of roaming information may include information indicating whether to request an acknowledgement (Ack), which is a response indicating that the Steering of roaming information from the UE has been successfully received.

[0187] The SOR information may include a list of recommended (or preferred) PLMN and access technology combinations and information indicating that (the list) is included, or information indicating that a secured packet and that (the packet) is included, or information indicating that the information indicating the list of recommended PLMN and access technology combinations is not included in the Steering of roaming information because there is no need to change the list of recommended PLMN and access technology combinations stored in the UE.

[0188] The SOR information and an Ack, which is a response indicating that the UE has successfully received the SOR information, may be transmitted and received in a SOR transparent container information element included in the NAS message.

[0189] The N1 NAS signaling connection is a connection between the UE and the network (AMF), and may be managed and exist independently for 3GPP access and non-3GPP access.

[0190] The state in which the N1 NAS signaling connection is established may be 5GMM-CONNECTED mode. The state in which the N1 NAS signaling connection is not established may be 5GMM-IDLE mode.

[0191] In other words, a state in which an N1 NAS signaling connection is established over 3GPP access may be expressed as the UE being in 5GMM-CONNECTED mode over 3GPP access, and a state in which an N1 NAS signaling connection is not established over 3GPP access may be expressed as the UE being in 5GMM-IDLE mode over 3GPP access.

[0192] Similarly, a state in which an N1 NAS signaling connection is established over non-3GPP access may be expressed as the UE being in 5GMM-CONNECTED mode over non-3GPP access, and a state in which an N1 NAS signaling connection is not established over non-3GPP access may be expressed as the UE being in 5GMM-IDLE mode over non-3GPP access.

[0193] The service type may be a type of service that the UE can perform and / or is currently performing. Specifically, the service indicated by the service type may be IMS registration related signaling, MMTEL voice call, MMTEL video call, MO SMS over NAS (SMSoNAS), and / or MO SMSoIP, etc.

[0194] Note that IMS may be an abbreviation for IP Multimedia Subsystem, MMTEL may be an abbreviation for multimedia telephony service, SMS may be an abbreviation for Short Message Service, NAS may be an abbreviation for Non-Access-Stratum, MO may be an abbreviation for Mobile Originated, and SMSoIP may be an abbreviation for SMS over IP (networks).

[0195] The service type may be the type of access attempt and / or the access category, and may indicate the service indicated by this information.

[0196] The type of access attempt is a type classified by a trigger that initiates access when a UE attempts access (when it initiates an access attempt), and may be used to determine the access category.

[0197] The access category is determined by the UE based on the type of access attempt. If the UE stores operator-defined access category definitions, the UE may use the operator-defined access category definitions to determine the access category.

[0198] The UE's PLMN selection mode includes an automatic mode and a manual mode.

[0199] The automatic mode is a mode in which PLMN selection is performed automatically. In this mode, the UE selects a PLMN and access technology combination in the order of priority of the PLMN and access technology combination. Specifically, in this mode, the PLMN selection selects the PLMN and access technology combination with the highest priority that is available to the UE. The automatic mode may also be referred to as an automatic network selection mode.

[0200] The manual mode is a mode in which the user can manually select a PLMN. In this mode, the UE (or MS) presents one or more selectable PLMNs to the user and performs roaming to a VPLMN only if the user selects one. The manual mode may also be referred to as a manual network selection mode.

[0201] SOR-CMCI (Steering of Roaming Connected Mode Control Information) is information that enables a network such as an HPLMN to control the timing at which a UE in connected mode transitions to disconnected mode for SOR. SOR-CMCI may be information based on an operator policy and / or an HPLMN policy. SOR-CMCI may be information set in each device or may be information notified from the NW to the UE.

[0202] Each device may manage and / or store multiple SOR-CMCIs for the UE, or may manage and / or store one SOR-CMCI.

[0203] The SOR-CMCI may include criteria belonging to one or more PDU sessions, and / or one or more service type criteria, and / or criteria (conditions) indicating when all criteria are met.

[0204] The criteria belonging to one PDU session included in one SOR-CMCI may include one S-NSSAI, one DNN, and / or one 5QI. The criteria belonging to one PDU session included in one SOR-CMCI may further include information indicating one access technology, information indicating one PDU session type, and / or one PDU session ID value. When the criteria belonging to one PDU session include information belonging to multiple PDU sessions, it may mean a combination of them.

[0205] If multiple PDU sessions are established, one SOR-CMCI may include criteria belonging to multiple PDU sessions, where each criterion may include one S-NSSAI, one DNN, one 5QI, information indicating the access technology, information indicating the PDU session type, and / or a PDU session ID value.

[0206] Specifically, when multiple PDU sessions are established, each S-NSSAI, and / or each DNN, and / or each 5QI used by each PDU session may be included in the SOR-CMCI, each access type for which each PDU session is established may be included in the SOR-CMCI, the PDU session type of each PDU session may be included in the SOR-CMCI, or the value of a PDU session ID that identifies each PDU session may be included in the SOR-CMCI.

[0207] The criteria for belonging to one PDU session included in one SOR-CMCI may include one or more S-NSSAIs, and / or one or more DNNs, and / or one or more 5QIs. The criteria for belonging to one PDU session included in one SOR-CMCI may further include information indicating one or more access technologies, and / or information indicating one or more PDU session types, and / or one or more PDU session ID values.

[0208] One service type criterion included in one SOR-CMCI may include information identifying one or more service types, and may include information indicating an MMTEL voice call, and / or information indicating an MMTEL video call, and / or information indicating an MO SMS over NAS, and / or information indicating an MO SMSoIP.

[0209] If multiple services are running, one SOR-CMCI may include multiple service type criteria, where each service type criteria may include information indicating an MMTEL voice call, information indicating an MMTEL video call, information indicating an MO SMS over NAS, and / or information indicating an MO SMSoIP, respectively.

[0210] Specifically, when multiple services are running, information identifying each service may be included in the SOR-CMCI.

[0211] Hereinafter, each criterion may mean a criterion belonging to a PDU session, and / or a service type criterion, and / or a criterion (condition) indicating a match with all criteria, or may be each piece of information belonging to a PDU session included in the criterion belonging to a PDU session (S-NSSAI, DNN, 5QI, etc.), and / or information identifying the service type included in the service type criterion, and / or information indicating a match with all criteria.

[0212] The SOR-CMCI may include a timer value mapped to each criterion. When the SOR-CMCI includes a timer value mapped to a criterion that indicates a match for all criteria, the timer value may be set shorter than the timer values ​​mapped to other criteria.

[0213] The SOR-CMCI may include a value indicating a priority associated with each criterion. The value indicating the priority may be referred to as a precedence value, and the priority of one or more criteria may be determined based on the precedence value. Alternatively, the priority may be indicated by the order of the criteria included in the SOR-CMCI. Specifically, the criteria may be sorted and managed so that the criteria with the highest priority are at the top.

[0214] The first timer is a timer for determining the timing at which a UE in connected mode transitions to disconnected mode for SOR. The first timer may be Tsor-cm of 3GPP. The first timer may be managed by the UE and / or the NW. The first timer may be managed for each PDU session, for each access type, for each combination of a PDU session and an access type, for each service type, for each PLMN, or for each UE. In the following, the timer value set in the first timer may be referred to as the first timer value.

[0215] In other words, one UE may manage one or more first timers, or one UE may manage one first timer. The first timer managed by the UE may be stored in association with a PDU session ID, information indicating an access type, information indicating a combination of a PDU session and an access type, a service type, and / or a PLMN ID.

[0216] Based on the SOR-CMCI used when selecting the timer value to be set in the first timer, the criteria to which the selected timer value is associated, and / or information belonging to the PDU session included in the criteria, and / or information indicating the service type included in the criteria, and / or information indicating the priority to which the criteria is associated may be managed in association with the first timer and / or the first timer value.

[0217] A PDU session identified by information associated with these first timers, or a PDU session using information associated with the first timers, may be referred to as a PDU session associated with the first timer, and a service identified by information associated with the first timer may be referred to as a service associated with the first timer.

[0218] Here, "managing the first timer" means that the first timer is started and / or stopped and / or expired and / or executed. In other words, "the UE and / or NW managing the first timer" means that the UE and / or NW starts and / or stops and / or expires and / or executes the first timer, and "the state in which the UE and / or NW manages the first timer" means that the UE and / or NW is executing the first timer.

[0219] Specifically, for example, when a UE and / or NW has established multiple PDU sessions, the UE and / or NW may manage a first timer for each PDU session, or may manage only one first timer.

[0220] Furthermore, for example, when the UE and / or NW establishes a first PDU session and a second PDU session on a 3GPP access and a third PDU session and a fourth PDU session on a non-3GPP access, the UE and / or NW may manage a first timer associated with the 3GPP access and a first timer associated with the non-3GPP access, or may simultaneously manage multiple first timers associated with each of the first to fourth PDU sessions.

[0221] Furthermore, for example, when the UE and / or NW establishes an MA PDU session that establishes user plane resources over both 3GPP access and non-3GPP access, the UE and / or NW may manage a first timer associated with the MA PDU session, or may simultaneously manage a first timer associated with the 3GPP access and a first timer associated with the non-3GPP access.

[0222] [2.7. Description of Identification Information in This Embodiment] Next, the identification information transmitted, received, stored, and managed by each device in this embodiment will be described.

[0223] In this embodiment, the first identification information may be capability information of UE_A10 indicating that UE_A10 supports the function of receiving, and / or recognizing, and / or storing, and / or processing information from the network indicating that a PLMN or a particular area of ​​the PLMN has applied or lifted a disaster condition.

[0224] Here, the information indicating that a PLMN or a specific area of ​​a PLMN has applied or removed a disaster condition may be information transmitted to a UE by the PLMN that applied or removed the disaster condition, or by another PLMN (PLMN#2) that has recognized that the PLMN (PLMN#1) has applied or removed the disaster condition. In this document, information indicating that a PLMN or a specific area of ​​a PLMN has applied or removed a disaster condition is also referred to as PLMN disaster condition information.

[0225] Here, the information indicating that a PLMN or a specific area of ​​the PLMN has applied a disaster condition may be a third identification information described below, and the information indicating that a PLMN or a specific area of ​​the PLMN has released the disaster condition may be a fifth identification information described below. In other words, the first identification information may be capability information of the UE indicating that the UE supports a function to process the third identification information and / or the fifth identification information.

[0226] The PLMN disaster status information received by the UE may be received from the PLMN to which the UE is registered or connected, or from a PLMN other than the PLMN to which the UE is registered or connected. Details will be described later in the description of the third to fifth identification information and procedures.

[0227] The second identification information in this embodiment may be capability information indicating that the PLMN or a particular area of ​​the PLMN supports the function of transmitting information to the UE indicating that a disaster state has been applied or lifted.

[0228] Conversely, the second identification information may be capability information indicating that the PLMN or a specific area of ​​the PLMN does not support the function of transmitting information indicating that a disaster state has been applied or lifted to the UE. Unless otherwise specified in this document, the second identification information refers to capability information indicating that the PLMN or a specific area of ​​the PLMN supports the function of transmitting information indicating that a disaster state has been applied or lifted to the UE.

[0229] Here, the core network may transmit the second identification information, for example, by including the second identification information in a response message, based on receiving the first identification information from the UE.

[0230] The third identification information in this embodiment may be identification information indicating that a PLMN has applied a disaster state and / or identification information indicating the PLMN that has applied a disaster state.

[0231] Here, the information indicating the PLMN to which the disaster state has been applied may be a PLMN ID, which is identification information of the PLMN to which the disaster state has been applied, and further, the third identification information may include one or more PLMN IDs.

[0232] In addition, here, the third identification information may be information transmitted to the UE by a PLMN to which a disaster state has been applied, or a PLMN to which the information has been notified from a PLMN to which a disaster state has been applied, or a PLMN that has recognized or determined that another PLMN is in a disaster state.

[0233] Furthermore, the third identification information may be a 5GMM (5GS Mobility Management) cause. Furthermore, the third identification information may be information indicating that a disaster state has been applied, or may be a 5GMM cause indicating that a disaster state has been applied.

[0234] Furthermore, the third identification information may be included in a NAS message sent by the core network to the UE, or may be included in a session management (SM) message sent by the core network to the UE, or may be information included in information broadcast by the base station to the cell and transmitted to the UE.

[0235] Furthermore, the UE that has received the third identification information may add the PLMN indicated by the third identification information to a list that manages PLMNs in a disaster state that is managed within the UE. More specifically, the list that manages PLMNs in a disaster state that is managed within the UE may be, but is not limited to, a forbidden PLMN list or a new forbidden PLMN list that takes the disaster state into consideration.

[0236] Furthermore, the UE that has received the third identification information may add the current PLMN to a list that manages PLMNs in a disaster state that is managed within the UE. In other words, the UE that has received the third identification information may add the PLMN ID of the current PLMN to a list that manages PLMNs in a disaster state that is managed within the UE.

[0237] The fourth identification information in this embodiment is identification information that indicates the PLMN to which the UE will roam (move) when the PLMN to which the UE is currently connected falls into a disaster state and roaming (movement) to another PLMN becomes necessary.

[0238] Here, the information indicating the PLMN to which the UE has roamed (moved) may be a PLMN ID, which is identification information of the PLMN to which the UE has roamed (moved), and further, the fourth identification information may include one or more PLMN IDs.

[0239] Also, here, the PLMN indicated by the fourth identification information may be a PLMN to which a disaster state does not apply.

[0240] Furthermore, the fourth identification information may be a 5GMM (5GS Mobility Management) cause. Furthermore, the fourth identification information may be information indicating that the disaster state of PLMN_A has been lifted, or may be a 5GMM cause indicating that the disaster state of PLMN_A has been lifted. Here, PLMN_A may be a PLMN where the PLMN_A was previously registered. Furthermore, PLMN_A may be a HPLMN.

[0241] Furthermore, the fourth identification information may be included in a NAS message sent by the core network to the UE, or may be included in a session management (SM) message sent by the core network to the UE, or may be information included in information broadcast by the base station to the cell and sent to the UE.

[0242] In addition, the PLMN included in the fourth identification information may be a PLMN that supports disaster roaming, where a PLMN that supports disaster roaming is a PLMN that can accept roaming of the UE when a PLMN to which the UE is registered or connected applies a disaster state.

[0243] The fourth identification information may include one or more PLMNs. The fourth identification information may be information included in a SOR (Steering of Roaming) transparent container information element (IE), or may be information not included in a SOR transparent container IE.

[0244] Furthermore, here, the UE may transition to a deregistered state based on the reception of the fourth identification information and register with the PLMN indicated by the fourth identification information. More specifically, the procedure for the UE to transition to the deregistered state may be a deregistration procedure initiated by the UE or the core network, or may be an implicit deregistration procedure. Detailed procedures and steps will be described later.

[0245] Furthermore, the UE that has received the fourth identification information may delete PLMN_A from a list that manages PLMNs in a disaster state that is managed internally by the UE. In other words, the UE that has received the fourth identification information may add the PLMN ID of PLMN_A to a list that manages PLMNs in a disaster state that is managed internally by the UE. Here, PLMN_A may be a PLMN that has been previously registered. Furthermore, PLMN_A may be a HPLMN.

[0246] The fifth identification information in this embodiment may be identification information indicating that the PLMN has lifted the disaster state, and / or identification information indicating that the PLMN is not in a disaster state, and / or identification information indicating a PLMN that has lifted the disaster state or a PLMN to which the disaster state is not applied.

[0247] Here, the information indicating the PLMN that is not in a disaster state and / or the PLMN that has lifted the disaster state may be a PLMN ID that is identification information of the PLMN that is not in a disaster state and / or the PLMN that has lifted the disaster state, and further, the fourth identification information may include one or more PLMN IDs.

[0248] In addition, here, the fifth identification information may be information transmitted to the UE by a PLMN that has lifted the disaster state, or a PLMN that has been notified of the information from the PLMN that lifted the disaster state, or a PLMN that has recognized or determined that another PLMN has lifted the disaster state.

[0249] Furthermore, the fifth identification information may be included in a NAS message sent by the core network to the UE, or may be included in a session management (SM) message sent by the core network to the UE, or may be information included in information broadcast by the base station to the cell and sent to the UE.

[0250] Furthermore, here, the UE that has received the fifth identification information may delete the PLMN indicated by the fifth identification information from a list that manages PLMNs in a disaster state that is managed within the UE. More specifically, the list that manages PLMNs in a disaster state that is managed within the UE may be, but is not limited to, a forbidden PLMN list or a new forbidden PLMN list that takes the disaster state into consideration.

[0251] Here, the third to fifth identification information may be identification information that combines the respective identification information. In other words, one identification information may indicate the application of a disaster state to a PLMN or the cancellation of the disaster state, or may be identification information that indicates one or more PLMNs that have applied or canceled the disaster state. Alternatively, it may be identification information that indicates that a PLMN has applied a disaster state or identification information that indicates a PLMN to which the disaster state has been applied, or may further be identification information that includes a PLMN to which the UE has roamed (moved) that has registered or connected to the PLMN to which the disaster state has been applied.

[0252] In this case, the UE may update the disaster state PLMN list managed by the UE within the UE based on the identification information that is a combination of the third to fifth identification information.

[0253] The sixth identification information in this embodiment may be information indicating the signaling overload of a PLMN that is not in a disaster state or information indicating a priority of the PLMN. Furthermore, the sixth identification information may be information indicating the signaling overload of a PLMN that has released the disaster state.

[0254] Here, the sixth identification information is, for example, information indicating signal load information or priority of one or more UE roaming destination PLMNs indicated by the fourth identification information, and a UE that has received the sixth identification information and / or the fourth identification information may select a PLMN based on the sixth identification information and taking into consideration the state or priority of the destination PLMN. More specifically, for example, a UE may select a destination PLMN based on the sixth identification information indicating that the destination PLMN has a low signal load and / or a high priority.

[0255] The information indicating the signal load of the PLMN and / or the information indicating the priority, which is included in the sixth identification information, may be processed together with the list of preferred PLMN / access technology combinations used in PLMN selection during roaming. More specifically, PLMN selection may be performed based on the priority indicated by the sixth identification information, instead of the priority according to the order of storage in the list of preferred PLMN / access technology combinations, which is used in normal PLMN selection.

[0256] Furthermore, the seventh identification information is information indicating disaster roaming. The seventh identification information may be a 5GS registration type IE indicating that the registration procedure is for disaster roaming. The seventh identification information may be configured as information separate from the 5GS registration type IE.

[0257] Furthermore, the eighth identification information is information indicating whether disaster roaming is enabled or not, or information indicating whether a disaster state is enabled or not. Here, whether disaster roaming is enabled or not may be expressed as a DRI (Disaster Roaming Indicator). That is, when the bit of the DRI indicates 1, it may indicate that disaster roaming is enabled. When the bit of the DRI indicates 0, it may indicate that disaster roaming is disabled. Also, whether a disaster state is enabled or not may be expressed as a DCI (Disaster Condition Indicator). That is, when the bit of the DCI indicates 1, it may indicate that a disaster state is enabled. When the bit of the DCI indicates 0, it may indicate that a disaster state is disabled.

[0258] 3. Embodiments of the present invention [3.1. Description of procedures used in each embodiment] Next, procedures used in each embodiment will be described. The procedures used in each embodiment include a registration procedure, a notification procedure, and a PLMN selection. Each procedure will be described below.

[0259] In each embodiment, as shown in FIG. 2, the HSS and UDM, PCF and PCRF, SMF and PGW-C, and UPF and PGW-U are each configured as the same device (i.e., the same physical hardware, the same logical hardware, or the same software). However, the contents described in this embodiment are also applicable to cases where these are configured as different devices (i.e., different physical hardware, different logical hardware, or different software). For example, data may be transmitted and received directly between these devices, or data may be transmitted and received via the N26 interface between the AMF and MME, or data may be transmitted and received via the UE.

[0260] 3.1.2. Registration Procedures First, the registration procedure will be described with reference to FIG. 6. Hereinafter, this procedure refers to the registration procedure. The registration procedure is a procedure initiated by the UE to register with the access network _B, and / or the core network _B, and / or the DN, and / or the PLMN. If the UE is not registered with a network, it can execute this procedure at any time, for example, when it is powered on. In other words, if the UE is in a deregistered state (5GMM-DEREGISTERED state), it can start this procedure at any time. Furthermore, each device (especially the UE and the AMF) can transition to a registered state (5GMM-REGISTED state) based on the completion of the registration procedure. Note that each registration state may be managed by each device for each access. Specifically, each device may independently manage the registration state (registered state or unregistered state) for 3GPP access and the registration state for non-3GPP access.

[0261] Furthermore, the registration procedure may be a procedure for updating the location registration information of the UE in the network, and / or for the UE to periodically notify the network of the status of the UE, and / or for updating certain parameters related to the UE in the network.

[0262] A UE may initiate a registration procedure when it moves across tracking areas (TAs). In other words, a UE may initiate a registration procedure when it moves to a TA different from the TA indicated in its TA list (TAI list or registration area). Furthermore, a UE may initiate this procedure when a running backoff timer or other timer expires. Furthermore, a UE may initiate a registration procedure when a context update for each device is required due to a PDU session disconnection or invalidation. Furthermore, a UE may initiate a registration procedure when a change occurs in the UE's capability information and / or preferences related to PDU session establishment. Furthermore, a UE may initiate a registration procedure periodically. Furthermore, a UE may initiate a registration procedure based on the completion of a UE configuration update procedure, a registration procedure, a PDU session establishment procedure, a PDU session management procedure, information received from the network in each procedure, or the expiration or stopping of a backoff timer. Note that the UE may perform the registration procedure at any timing, not limited to these.

[0263] The procedure for the UE to transition from a state where it is not registered in the network to a state where it is registered may be referred to as an initial registration procedure or a registration procedure for initial registration, and the registration procedure performed when the UE is registered in the network may be referred to as a registration procedure for mobility and periodic registration update or a mobility and periodic registration procedure.

[0264] In addition, the UE may perform PLMN selection before the registration procedure or in the initial state of the registration procedure to select and determine the PLMN required by the UE.

[0265] In Figure 6, new AMF141 indicates the AMF to which UE_A10 is registered through this procedure, and old AMF142 refers to the AMF to which the UE was registered through a procedure prior to this procedure. If no AMF changes occur during this procedure, the interface between old AMF142 and new AMF141 and the procedure between old AMF142 and new AMF141 do not occur, and new AMF141 may be the same device as old AMF142. Note that in this document, when referring to AMF, it may mean new AMF141, old AMF142, or both. Furthermore, new AMF141 and old AMF142 may be AMF140.

[0266] First, UE_A10 starts the registration procedure by sending a registration request message to new AMF141 (S600) (S602) (S604). Specifically, the UE sends an RRC message including the registration request message to 5G AN120 (or gNB) (S600). Note that the registration request message is a NAS message transmitted and received on the N1 interface. Also, the RRC message may be a control message transmitted and received between the UE and 5G AN120 (or gNB). Also, the NAS message is processed in the NAS layer, and the RRC message is processed in the RRC layer. Note that the NAS layer is a layer higher than the RRC layer.

[0267] Here, UE_A10 can transmit the first identification information and / or the seventh identification information by including them in a registration request message and / or an RRC message. Furthermore, UE_A10 may transmit the registration request message and / or the RRC message by including identification information indicating the type of this procedure. Here, the identification information indicating the type of this procedure may be a 5GS registration type IE, and may be information indicating that this procedure is a registration procedure for initial registration, for registration information update due to movement, for periodic registration information update, for emergency registration, or for disaster roaming. Note that the seventh identification information may be a 5GS registration type IE indicating that this is a registration procedure for disaster roaming.

[0268] In order to notify the network of the functions supported by UE_A10, UE_A10 may include the capability information of the UE in the registration request message, and may include the first identification information as the capability information of the UE. Here, the capability information of the UE may be the 5G MM capability of 5GS.

[0269] UE_A10 may transmit this identification information in a different control message, for example, a control message of a layer lower than the RRC layer (for example, the MAC layer, RLC layer, or PDCP layer).By transmitting this identification information, UE_A10 may indicate that UE_A10 supports each function, or may indicate a UE request, or may indicate both.In addition, the information indicating support for each function and the information indicating a request for use of each function may be transmitted and received as the same identification information, or may be transmitted and received as different identification information.

[0270] Furthermore, UE_A10 may select and decide whether to send the first identification information to the network based on the UE's capability information, and / or UE policy, and / or UE status, and / or user registration information, and / or context held by the UE, etc.

[0271] If UE_A10 has the capability to identify and process the combination information of PLMN ID and NSSAI (S-NSSAI) supported by the PLMN included in the third identification information and / or fourth identification information used for PLMN selection after movement, UE_A10 may send the first identification information in the registration request message.By sending the first identification information, UE_A10 may indicate to the network that it supports the capability to receive, and / or recognize, and / or store, and / or process information from the network indicating that a PLMN or a specific area of ​​the PLMN has applied or lifted a disaster condition.

[0272] Furthermore, UE_A10 may indicate that it requests network capability information indicating that the network supports the function corresponding to the first identification information by sending the first identification information in a registration request message.

[0273] UE_A10 may include information other than the first identification information in the registration request message and / or the RRC message containing the registration request message, for example, the UE ID and / or PLMN ID and / or AMF identification information and / or requested NSSAI.

[0274] Here, the AMF identification information may be information that identifies an AMF or a set of AMFs, for example, 5G-S-TMSI (5G S-Temporary Mobile Subscription Identifier) ​​or GUAMI (Globally Unique AMF Identifier).

[0275] If UE_A10 stores "an allowed NSSAI associated with the PLMN requested by the UE and the access type requested by the UE," and / or stores "a configured NSSAI for the requested PLMN," and / or stores "a default configured NSSAI," the UE may include the requested NSSAI in a registration request message and send it to the requested PLMN.

[0276] Alternatively, if the UE stores an "allowed NSSAI associated with a PLMN other than the PLMN requested by the UE and the access type requested by the UE," and if that allowed NSSAI or an S-NSSAI included in the allowed NSSAI is further associated with the requested PLMN, UE_A10 may include the requested NSSAI in a registration request message and send it to the requested PLMN.

[0277] Here, the case where an allowed NSSAI associated with a PLMN other than the PLMN requested by the UE or an S-NSSAI included in the allowed NSSAI is associated with the requested PLMN may mean, for example, that UE_A10 stores the allowed NSSAI in association with multiple PLMNs (the requested PLMN and other PLMNs).

[0278] Alternatively, a case where an allowed NSSAI associated with a PLMN different from the PLMN requested by the UE or an S-NSSAI included in the allowed NSSAI is associated with the requested PLMN may be a case where the UE stores an allowed NSSAI associated with a PLMN different from the PLMN requested by the UE or an S-NSSAI included in the allowed NSSAI, and a PLMN list that supports that S-NSSAI, and the PLMN requested by the UE is included in that PLMN list.

[0279] UE_A10 may also include in the requested NSSAI an S-NSSAI included in an allowed NSSAI associated with a PLMN different from the PLMN requested by the UE.

[0280] Alternatively, UE_A10 may include the mapped S-NSSAI of an S-NSSAI included in an allowed NSSAI associated with a PLMN different from the PLMN requested by the UE in the 5GS Requested mapped NSSAI.

[0281] Alternatively, in the registration request procedure to the VPLMN, UE_A10 may include the S-NSSAI contained in the allowed NSSAI associated with the HPLMN in the 5GS Requested mapped NSSAI and send it to the network.

[0282] In addition, UE_A10 may initiate a PDU session establishment procedure during the registration procedure by sending an SM message (e.g., a PDU session establishment request message) included in the registration request message, or by sending an SM message (e.g., a PDU session establishment request message) together with the registration request message.

[0283] When the 5G AN 120 (or gNB) receives an RRC message including a registration request message, it selects an AMF to which to transfer the registration request message (S602). Note that the 5G AN 120 (or gNB) can select an AMF based on one or more pieces of identification information included in the registration request message and / or the RRC message including the registration request message. Specifically, the 5G AN (or gNB) may select a new AMF 141 to which to send the registration request message based on the first identification information.

[0284] For example, the 5G AN 120 (or gNB) may select, based on the first identification information, an AMF that supports a function corresponding to the capability information indicated by the first identification information. Specifically, the 5G AN (or gNB) may select an AMF that corresponds to the UE capability information indicated by the first identification information and has a function for generating and transmitting information indicating that a PLMN to which the UE is registered or another PLMN has applied or canceled a disaster state, or information indicating a PLMN that has applied or canceled a disaster state.

[0285] Note that the method for selecting an AMF is not limited to this, and the 5G AN (or gNB) may select an AMF based on other conditions. The 5G AN (or gNB) extracts a registration request message from the received RRC message and transfers the registration request message to the selected new AMF (S604). Note that if the first identification information is not included in the registration request message but is included in the RRC message, the identification information included in the RRC message may be transferred to the selected AMF (new AMF 141) together with the registration request message (S604).

[0286] When the new AMF 141 receives the registration request message, it may recognize based on the seventh identification information that the UE is requesting disaster roaming and / or that disaster roaming has occurred.

[0287] When the new AMF 141 receives a registration request message, it can execute a first condition determination. The first condition determination is for determining whether the network (or the new AMF 141) accepts the UE's request. When the first condition determination is true, the new AMF 141 executes the procedures from S606 to S612. On the other hand, when the first condition determination is false, the new AMF 141 may execute the procedure of S610 without executing the procedures from S606 to S608.

[0288] Alternatively, the new AMF 141 may request the UE context from the old AMF 142 and perform the first condition determination after receiving the UE context from the old AMF 142 (S606, S608). In this case, the new AMF 141 may execute S610 and / or S612 if the first condition determination is true. On the other hand, the new AMF 141 may execute S610 if the first condition determination is false.

[0289] Here, if the first condition determination is true, the control message sent and received in S610 may be a Registration accept message, and if the first condition determination is false, the control message sent and received in S610 may be a Registration reject message.

[0290] Furthermore, the first condition determination may be performed based on the receipt of a registration request message, and / or each identification information contained in the registration request message, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the AMF, etc.

[0291] For example, if the network permits the UE's request, the first condition determination may be true, and if the network does not permit the UE's request, the first condition determination may be false. Furthermore, if the network to which the UE is registered and / or a device within the network supports the function requested by the UE, the first condition determination may be true, and if the function requested by the UE is not supported, the first condition determination may be false. Furthermore, if the identification information to be transmitted and received is permitted, the first condition determination may be true, and if the identification information to be transmitted and received is not permitted, the first condition determination may be false.

[0292] Furthermore, if the S-NSSAI included in the requested NSSAI received by the AMF from the UE is information identifying a slice requiring an NSSAA procedure, and if the AMF stores the result of the NSSAA procedure for the corresponding S-NSSAI for the UE as successful, the first condition determination may be true. Alternatively, if there is no S-NSSAI to allow for the UE and there are no plans to assign an allowed NSSAI to the UE in the future, the first condition determination may be false.

[0293] Furthermore, if the S-NSSAI included in the requested NSSAI received by the AMF from the UE is information identifying a slice that requires management of the maximum number of UEs connected to the slice, and if the maximum number of UEs has not been reached, the first condition determination may be true. Alternatively, even if there is no S-NSSAI to allow for the UE, if it is expected that an allowed NSSAI will be assigned to the UE in the future, the first condition determination may be true.

[0294] When the AMF allocates the first NSSAI to the UE when there is no S-NSSAI to grant to the UE, the first condition determination may be true or false.

[0295] If the AMF indicated in the AMF identification information included in the message received by new AMF 141 from the UE is old AMF 142, new AMF 141 executes the procedures of S606 and S608, and if the AMF indicated in the AMF identification information included in the message received by new AMF 141 from UE_A10 is new AMF 141, new AMF 141 does not execute the procedures of S606 and S608. In other words, if an AMF change occurs due to this procedure, the procedures of S606 and S608 are executed, and if no AMF change occurs, the procedures of S606 and S608 are skipped.

[0296] The UE context transfer procedure (S606, S608) will be described. The new AMF 141 sends a UE context request message to the old AMF 142 (S606). The old AMF 142 sends the UE context to the new AMF 141 based on the received UE context request message. The new AMF 141 generates a UE context based on the received UE context.

[0297] Here, the UE context transmitted from new AMF 141 to old AMF 142 may include a UE ID and an allowed NSSAI. Furthermore, the UE context may include a configured NSSAI and / or a rejected NSSAI, an NSSAI and / or a pending NSSAI, and / or a first NSSAI. Furthermore, the allowed NSSAI, and / or the configured NSSAI, and / or the rejected NSSAI, and / or the pending NSSAI, and / or the first NSSAI included in the UE context, and the S-NSSAI included in each NSSAI may be linked to information on whether notification to the UE has been completed.

[0298] The UE context may also include information on S-NSSAI that requires an NSSAA procedure, and / or information indicating that the NSSAA procedure has been completed for the UE, that authentication has been successful, and / or information indicating that authentication has failed.

[0299] The UE context may also include information on S-NSSAI, which requires management of the maximum number of UEs connected to a slice, and / or information indicating that the maximum number of UEs has been reached, and / or information indicating whether the maximum number of UEs connected to a slice has been reached.

[0300] In addition, information regarding the characteristics of these S-NSSAIs may be managed as a single piece of information. Specifically, the network may associate and store, for each S-NSSAI, information indicating whether NSSAA is required, whether NSSAA was successful, whether management of the maximum number of UEs connecting to the slice is required, and whether the maximum number of UEs connecting to the slice has been reached.

[0301] The new AMF 141 may send a control message to the UE based on the determination of the first condition determination and / or based on receiving the UE context from the old AMF 142 (S610). The control message may be a registration accept message or a registration reject message. The following describes the case where the control message sent to the UE is a registration accept message.

[0302] The new AMF 141 may transmit a control message including at least the second identification information and / or the eighth identification information. By transmitting this identification information and / or the control message, the new AMF 141 may indicate that the network supports the function indicated by the identification information, that the UE request has been accepted, that the request from the UE is not permitted or supported, or a combination of these.

[0303] Here, the second identification information may be capability information indicating that the new AMF 141 and / or the core network supports the function corresponding to the capability information indicated by the first identification information received from the UE.

[0304] Furthermore, when new AMF 141 receives first identification information from the UE, even if new AMF 141 does not include second identification information in the control message that is a registration accept message, new AMF 141 may indicate to the UE that new AMF 141 and / or the core network recognize the capability information of the UE indicated by the first identification information and / or that new AMF 141 and / or the core network supports the function corresponding to the capability indicated by the first identification information. Conversely, when new AMF 141 does not include second identification information in the control message that is a registration message, new AMF 141 may indicate to the UE that new AMF 141 and / or the core network do not recognize the capability information of the UE indicated by the first identification information and / or that new AMF 141 and / or the core network do not support the function corresponding to the capability indicated by the first identification information.

[0305] Furthermore, if the new AMF 141 does not receive the first identification information from the UE, the new AMF 141 may include the second identification information in the control message and transmit it, or may not include the second identification information and not transmit it.

[0306] The new AMF141 may further include the configured NSSAI, and / or the allowed NSSAI, and / or the rejected NSSAI, and / or the pending NSSAI, and / or the first NSSAI in a control message and send it to UE_A10.

[0307] When sending the control message, new AMF141 does not have an allowed NSSAI (S-NSSAI) for the UE, but if it plans to perform an NSSAA procedure after completing this procedure or in parallel with this procedure, or if an NSSAA procedure is currently being performed between the UE and the network, or if it has sent a pending NSSAI in the control message, it may send an empty value in the allowed NSSAI.

[0308] Furthermore, the AMF may select and decide whether to include the second identification information in the control message based on each identification information received from the UE, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the AMF, etc.

[0309] Furthermore, when the control message is a registration acceptance message, the AMF can include an SM message (e.g., a PDU session establishment acceptance message) in the registration acceptance message and send it, or can send an SM message (e.g., a PDU session establishment acceptance message) together with the registration acceptance message. However, this sending method may also be performed when an SM message (e.g., a PDU session establishment request message) is included in the registration request message. Also, this sending method may be performed when an SM message (e.g., a PDU session establishment request message) is sent together with the registration request message. By performing such a sending method, the AMF can indicate that the procedure for SM has been accepted in the registration procedure.

[0310] In addition, the AMF may indicate that the UE's request has been accepted by sending a registration acceptance message, or may indicate that the UE's request has been rejected by sending a registration rejection message, based on the received identification information, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the AMF, etc.

[0311] The UE receives a control message via the 5G AN (gNB) (S608). If the control message is a registration acceptance message, the UE can recognize by receiving the registration acceptance message that the UE's request in the registration request message has been accepted and the contents of various identification information included in the registration acceptance message. Alternatively, if the control message is a registration rejection message, the UE can recognize by receiving a registration rejection message that the UE's request in the registration request message has been rejected and the contents of various identification information included in the registration rejection message. Furthermore, if the UE does not receive a control message even after a predetermined period has elapsed since sending the registration request message, the UE may recognize that the UE's request has been rejected.

[0312] Furthermore, the UE may recognize whether disaster roaming is enabled or whether a disaster state is enabled based on the received eighth identification information.

[0313] If the control message is a registration accept message, the UE may further transmit a registration complete message to the AMF via the 5G AN (gNB) as a response message to the registration accept message (S610). When the UE receives an SM message such as a PDU session establishment accept message, the UE may transmit an SM message such as a PDU session establishment complete message in the registration complete message, or may indicate that the SM procedure has been completed by including the SM message. Here, the registration complete message is an NAS message transmitted and received on the N1 interface, but is transmitted and received between the UE and the 5G AN (gNB) in an RRC message.

[0314] The AMF receives a registration completion message via the 5G AN (gNB) (S612). In addition, each device completes this procedure based on the transmission and reception of the registration acceptance message and / or the registration completion message.

[0315] Alternatively, each device may complete the registration procedure based on sending and receiving a registration rejection message.

[0316] Each device may transition to or maintain a state in which the UE is registered in the network (RM_REGISTERED state or 5GMM-REGISTERED state) based on sending and receiving a registration accept message and / or a registration complete message, or may transition to or maintain a state in which the UE is not registered in the network on the access from which the registration reject message was received for the current PLMN (RM_DEREGISTERED state or 5GMM-DEREGISTERED state) based on sending and receiving a registration reject message. Also, the transition to each state of each device may be based on sending and receiving a registration complete message or completion of the registration procedure.

[0317] Furthermore, each device may perform processing based on the information transmitted and received during the registration procedure based on the completion of the registration procedure. For example, if the device transmits or receives information indicating that some of the UE's requests have been rejected, the device may recognize the reason why the UE's requests have been rejected. Furthermore, each device may perform this procedure again based on the reason why the UE's requests have been rejected, or may perform the registration procedure for core network_A or another cell.

[0318] Furthermore, the UE may store the identification information received with the registration accept message and / or the registration reject message and may recognize the network's decision based on the completion of the registration procedure.

[0319] Furthermore, the UE may delete one or more stored NSSAIs based on the completion of the registration procedure. Specifically, based on the completion of this procedure, if UE_A10 transitions to an unregistered state on both accesses (3GPP access and non-3GPP access) for the current PLMN, UE_A10 may delete the first rejected NSSAI and / or the third rejected NSSAI and / or the first NSSAI that it stores.

[0320] Furthermore, based on the completion of this procedure, if UE_A10 transitions to an unregistered state on an access (3GPP access and non-3GPP access) for the current PLMN, or if UE_A10 successfully completes the registration procedure in the new registration area, or if UE_A10 transitions to an unregistered state or a registered state on an access as a result of performing the registration procedure in the new registration area, UE_A10 may delete the second rejected NSSAI associated with the current PLMN, the current registration area, and / or its access type.

[0321] Furthermore, each device may initiate the registration procedure again upon expiration or stopping of the back-off timer.

[0322] Additionally, each device may initiate the registration process again based on the updated NSSAI it stores.

[0323] Furthermore, each device may initiate an SM procedure by sending or receiving an SM message based on the UE transitioning to or maintaining a state in which it is registered with the network (RM_REGISTERED state or 5GMM-REGISTERED state).

[0324] [3.1.3. Notification Procedures] Next, the notification procedure will be explained with reference to Figure 7. In this chapter, the notification procedure will also be referred to as this procedure. The purpose of this procedure may be to notify a UE that a PLMN has applied or released a disaster state, or to further notify a UE that is registered or connected to a PLMN that has applied a disaster state (PLMN D) of information about a roaming destination PLMN (PLMN A) and / or information for selecting a roaming destination PLMN.

[0325] This procedure may be a procedure in which the core network sends to the UE any or all of the information indicated by the third to sixth identification information based on the first identification information sent by UE_A10 and / or the second identification information sent by the core network in the registration procedure of Chapter 3.1.2.

[0326] Here, this procedure may be a network-initiated or UE-initiated procedure, and more specifically, may be, for example, a registration procedure for periodic or arbitrary registration updates, and / or a Generic UE configuration update procedure, and / or a network-initiated NAS transport procedure, and / or a network-initiated de-registration procedure, and / or a cell broadcast.

[0327] This procedure may begin with the AMF 140 and / or the 5G AN 120 and / or the core network sending a notification message to the UE (S700).

[0328] Here, the notification message may be, but is not limited to, a registration accept message, or a registration reject message, or a de-registration request message, or a configuration update command message, or a DL NAS TRANSPORT message, or a cell broadcast from the 5G AN120.

[0329] The notification message may be a NAS message.

[0330] Further, here, the AMF 140 and / or the 5G AN 120 may include one or more of the third to sixth identification information in the notification message and send it to the UE.

[0331] Next, the UE that receives the notification message may or may not send a notification response message to the notification message to the AMF 140 and / or 5G AN 120 (S702).

[0332] Here, the notification response message may be, but is not limited to, a registration complete message, a configuration update complete message, or a de-registration accept message, and may be a response message corresponding to the notification message received by the UE.

[0333] In addition, this procedure may be completed based on the UE receiving a notification message (S700) and / or transmitting a notification response message from the UE to the AMF 140 and / or the 5G AN 120 and / or the core network (S702).

[0334] In the following description of each procedure and / or process, the UE may be registered with any PLMN using the registration procedure described in Section 3.1.2. Unless otherwise specified, the transmission of a notification message means that it is sent by the AMF 140 and / or the 5G AN 120 and / or the core network.

[0335] Next, the behavior or processing of a UE that receives a notification message containing one or more of the third to sixth identification information in this procedure will be described.

[0336] The UE receives a notification message from the core network. The notification message may include one or more of the third to sixth identities. In other words, the UE may receive one or more of the third to sixth identities from the core network.

[0337] First, the case where the UE is registered or connected to a PLMN (PLMN D) to which a disaster condition applies will be described.

[0338] The UE receives a notification message from the core network. The notification message may include one or more of the third to sixth identities. In other words, the UE may receive one or more of the third to sixth identities from the core network.

[0339] When the UE receives the notification message including the third identity and / or the fourth identity from the AMF 140 and / or the 5G AN 120 and / or the core network, the UE recognizes the PLMN to which the disaster state applies based on the third identity, and since the PLMN is the PLMN to which the UE is connected or registered (PLMN D), the UE may execute a procedure to transition to a deregistered state. Here, the procedure to transition to a deregistered state may be a UE-initiated or network-initiated deregistration procedure, implicit deregistration, etc. The UE that has entered the deregistered state may recognize or select a destination PLMN based on the fourth identity.

[0340] Here, based on the identification information included in the notification message, the behavior or processing of the UE that has transitioned to the unregistered state may be any of the following.

[0341] For example, if the UE receives the third identification information in the notification message but does not receive the fourth identification information, the UE that transitioned to the unregistered state may perform PLMN selection for normal roaming based on the list of preferred PLMN / access technology combinations, excluding the PLMN for which the disaster state applies.

[0342] Furthermore, for example, when a sixth identification information is received in addition to the third identification information and the fourth identification information, a UE that has transitioned to an unregistered state may perform PLMN selection based on the sixth identification information if there are multiple roaming destination PLMNs indicated by the fourth identification information.

[0343] Next, a case where the UE is registered or connected to a PLMN (PLMN A) to which a disaster state does not apply will be described.

[0344] When the UE receives the notification message including the third identification information and / or the fourth identification information and / or the sixth identification information, the UE recognizes the PLMN to which the disaster state applies based on the third identification information, and since the PLMN is not the PLMN to which the UE is registered or connected, the UE may not transition to an unconnected state and may be able to communicate using the PLMN to which the UE is currently registered or connected (current PLMN); further, the UE may recognize that the procedure is prohibited for the PLMN indicated by the third identification information, and add the PLMN indicated by the third identification information to a prohibited PLMN list for the disaster state.

[0345] Furthermore, when the UE receives the notification message including the third identity, the UE may recognize that a disaster state has been applied to the current PLMN and may add the current PLMN to a forbidden PLMN list for the disaster state. In other words, when the UE receives the notification message including the third identity, the UE may recognize that the current PLMN cannot be used due to the application of the disaster state and may add a PLMN ID indicating the current PLMN to a forbidden PLMN list for the disaster state.

[0346] Conversely, when the UE receives the notification message including the fourth identification information, the UE may recognize that the disaster state of PLMN_A has been lifted and may delete PLMN_A from the forbidden PLMN list for the disaster state. In other words, when the UE receives the notification message including the fourth identification information, the UE may recognize that PLMN_A is available due to recovery from the disaster state and may delete the PLMN ID indicating PLMN_A from the forbidden PLMN list for the disaster state. Here, PLMN_A may be a PLMN that was previously registered. Furthermore, PLMN_A may be a HPLMN.

[0347] Here, based on the identification information included in the notification message, the behavior or processing of the UE that has not transitioned to the unregistered state may be any of the following.

[0348] For example, a UE that receives a notification message including the fifth identification information in addition to the third identification information and / or the fourth identification information and / or the sixth identification information may roam to the PLMN indicated by the fifth identification information. Note that detailed processing including the identification information will be described in the first to fourth embodiments below.

[0349] This procedure may be performed based on a PLMN initiating or terminating a disaster state, a PLMN receiving notification from another PLMN that a disaster state has been initiated or terminated, or a PLMN detecting or recognizing that another PLMN has initiated or terminated a disaster state through means other than notification. Triggers or conditions for this procedure are not limited to these.

[0350] 3.1.4. PLMN Selection Next, the process related to PLMN selection will be described.

[0351] Generally, PLMN selection is a process performed by a UE in an unregistered state to select a PLMN to register to before performing a registration procedure, but in this embodiment, the PLMN selection may be performed by the UE mainly based on the PLMN applying or canceling a disaster state.

[0352] Furthermore, PLMN selection may be a process performed by the UE, for example, when a disaster state occurs in the PLMN to which the UE is registered or connected, or in a particular area of ​​the PLMN, making it necessary to roam to another network (PLMN), or when mobility makes it necessary to switch from the PLMN to which the UE is currently registered and / or connected (here, the HPLMN) to another PLMN (a VPLMN), or when the UE is powered on in an area other than the HPLMN.

[0353] More specifically, PLMN selection may be a process performed in the network in which the disaster state applies, such as a UE-initiated or network-initiated de-registration procedure or implicit de-registration, when, for example, a PLMN to which the UE is registered or connected or a specific area of ​​the PLMN is in a disaster state, making it necessary for the UE to roam to another network (PLMN).

[0354] The details of this procedure will be further described in the first to fourth embodiments.

[0355] Furthermore, in this embodiment, the PLMN selection may be performed based on the SOR transparent container information element received and stored by UE_A10 in the registration procedure and / or update procedure, regardless of the identification information received by the UE in the notification procedure, etc., and the PLMN selection may be performed in an automatic mode, or in a manual mode, which is performed manually by the user based on the available PLMNs indicated by UE_A10. Here, the PLMN selection in the automatic mode may select the combination with the highest priority from the combinations of PLMN ID and access technology, and use it in the registration procedure to be performed next. Here, the priority may be the order in which the combinations of PLMN and access technology are stored, and the PLMN ID included in the combination of PLMN ID and access technology stored first may have the highest priority.

[0356] [3.2. First embodiment] A first embodiment of the present invention is an embodiment including a procedure and processing for notifying a UE by using an NAS message in the notification procedure described in Section 3.1.3 when a PLMN to which the UE is registered or connected applies a disaster state. Note that the NAS message may be transmitted and received during, for example, a registration procedure for periodic or arbitrary registration update, a generic UE configuration update procedure, a network-initiated NAS transport procedure, and / or a network-initiated de-registration procedure.

[0357] This embodiment may be implemented by a combination of one or more procedures or processes described in Chapter 3.1, and may also be an embodiment in which, in the registration procedure described in Chapter 3.1.2, the UE sends a registration request message including first identification information to the core network and the message is accepted, or the UE receives an acceptance message including second identification information from the core network.

[0358] In this embodiment, for example, when the UE receives the notification message described in 3.1.3. including the third identification information and / or the fourth identification information and / or the sixth identification information as a NAS message, the UE may recognize the PLMN to which the disaster state applies based on the third identification information, and if the PLMN is a PLMN to which the UE is connected or registered, perform a procedure to transition to an unregistered state, and if the PLMN is not a PLMN to which the UE is connected or registered, store the PLMN ID included in the third identification information.

[0359] Subsequently, the UE that has completed the procedure for transitioning to the unregistered state may perform PLMN selection based on the fourth and / or sixth identification information. The following detailed procedures will be further described in the second to fourth embodiments.

[0360] In this embodiment, the same procedure or processing may be performed when the PLMN to which the UE is registered or connected cancels the disaster state. The notification of the cancellation of the disaster state by the PLMN may be performed by the UE receiving, for example, a notification message including the fifth identification information.

[0361] [3.3. Second embodiment] The second embodiment of the present invention relates to the behavior of a UE when a PLMN to which the UE is registered or connected applies or cancels a disaster state and the network notifies the UE that the disaster state has been applied or canceled. In other words, this is an example of the behavior of a UE based on the UE receiving, from the network, information indicating that a PLMN or a specific area of ​​the PLMN has applied or canceled a disaster state. Hereinafter in this section, the second embodiment will also be referred to as the present embodiment.

[0362] This embodiment may be implemented by a combination of one or more procedures or processes described in Chapter 3.1, and may also be an embodiment in which, in the registration procedure described in Chapter 3.1.2, the UE sends a registration request message including first identification information to the core network and the message is accepted, or the UE receives an acceptance message including second identification information from the core network.

[0363] Furthermore, this embodiment may be the case where, in the registration procedure described in Chapter 3.1.2, the UE sends a registration request message including first identification information to the core network, and the core network and / or a device within the core network supports a function corresponding to the first identification information, and may further be performed by a combination of one or more procedures or processes described in Chapter 3.1.

[0364] First, in this embodiment, we will describe the behavior or behavior constraints regarding procedures between the UE and the network when a notification indicating that a PLMN has applied or canceled a disaster state or information (one or more PLMN IDs) of a PLMN that has applied or canceled a disaster state is received.

[0365] In this embodiment, when the UE receives, for example, third identification information as information indicating that one or more PLMNs or areas of a PLMN have applied a disaster state through the notification procedure described in Section 3.1.3, the UE must not perform mobility management procedures and / or session management procedures, except for the procedures described below, for the PLMN ID (PLMN D) indicated by the third identification information. More specifically, for example, when the UE is registered or connected to PLMN D, upon receiving information indicating that the PLMN (PLMN D) has applied a disaster state, the UE may be permitted to perform procedures other than the UE-initiated PDU session release procedure and / or the de-registration procedure with PLMN D, or may be prohibited from performing all UE-initiated procedures and / or may be permitted to perform only network-initiated procedures. More specifically, the procedures for which the UE is prohibited may be, but are not limited to, a PDU session establishment procedure, a PDU session modification procedure, a service request procedure, and a registration procedure for mobility and periodic registration update. Conversely, the procedure allowed for the UE may be, but is not limited to, implicit de-registration, a UE initiated de-registration procedure, or a core network initiated de-registration procedure.

[0366] In addition, here, if the UE is registered and / or a PDU session is established with PLMN D and all procedures are prohibited or cannot be performed, an implicit deregistration or release of the PDU session by local release may be performed.

[0367] Conversely, if the UE receives, for example, fifth identification information as information indicating that one or more PLMNs or PLMN areas have lifted the disaster state, the UE may be permitted to perform all mobility management procedures and / or session management procedures for the PLMN ID (PLMN A) indicated by the fifth identification information. The execution of each of the above procedures may be determined based on signal load information for each PLMN and / or a priority indicated by the network, as described in the third embodiment below. Details are provided in Section 3.4.

[0368] Next, in this embodiment, the behavior regarding the handling of the information within the UE when a notification indicating that a PLMN has applied or released a disaster state or information (one or more PLMN IDs) of the PLMN that has applied or released a disaster state is received will be described.

[0369] In this embodiment, when the UE receives, for example, third identification information as information indicating that a disaster state has been applied to any one or more PLMNs or PLMN areas through the notification procedure described in Chapter 3.1.3, the UE may add the PLMN ID (PLMN D) indicated by the identification information to a forbidden PLMN list for a disaster state and / or a normal forbidden PLMN list managed within the UE for managing PLMN IDs for which registration is prohibited.

[0370] In addition, zero or more PLMN IDs included in the forbidden PLMN list and / or the forbidden PLMN list for a disaster state are PLMNs to which a disaster state applies, and as described above, the UE should not perform procedures for registration and / or connection to these PLMNs. In other words, the UE may be prohibited from performing any procedures to PLMN IDs included in the forbidden PLMN list.

[0371] On the other hand, conversely, in this embodiment, when the UE receives, for example, fifth identification information from the AMF 140 and / or the 5G AN 120 and / or the core network through the notification procedure described in Chapter 3.1.3 as information indicating that one or more PLMNs or PLMN areas have lifted the disaster state, the UE may delete the PLMN ID (PLMN A) indicated by the identification information from a forbidden PLMN list for the disaster state and / or a normal forbidden PLMN list managed internally by the UE for managing PLMN IDs for which registration is prohibited. In other words, when the UE receives the fifth identification information from the PLMN or core network to which the UE is registered or connected. Based on the reception of the fifth identification information, the UE may delete the PLMN ID indicated by or included in the fifth identification information from a forbidden PLMN list for the disaster state and / or a normal forbidden PLMN list managed internally by the UE.

[0372] Note that the removal of a PLMN ID from the prohibited PLMN list due to a disaster state is not limited to this, and may be performed based on turning the UE power on / off or inserting / removing a USIM.

[0373] Furthermore, PLMN IDs not included in the forbidden PLMN list may be PLMN IDs for which a disaster state does not apply or for which the UE is not aware that a disaster state applies, and the UE may perform processes such as PLMN selection and / or subsequent mobility management procedures and / or session management procedures based on information included in, for example, the SOR transparent container information element.

[0374] [3.4. Third embodiment] A third embodiment of the present invention relates to a process in which a UE selects a PLMN based on information received when a disaster state occurs in a PLMN to which a UE is registered or connected, and the network notifies the UE of information including the fact that a disaster state has occurred.

[0375] One of the objectives of this embodiment is to avoid a load caused by a concentration of accesses for registration or connection on another PLMN (including PLMN#1) when a UE roams from a PLMN (PLMN#1) to another PLMN (e.g., PLMN(PLMN#2)) because a disaster state has been applied to the PLMN (PLMN#1). Another objective of this embodiment is to avoid a load caused by a concentration of accesses for registration or connection on another PLMN (including PLMN#1) when a UE that has registered or connected to another PLMN (e.g., PLMN#2) because a disaster state has been applied to the PLMN (PLMN#1) returns to the other PLMN (including PLMN#1) because the disaster state applied to PLMN#1 has been lifted.

[0376] [3.4.1] Here, it is assumed that when a disaster state is applied to a first PLMN (also referred to as PLMN#1) where the UE is registered, the UE selects a second PLMN (also referred to as PLMN#2) and receives the first list and the second list in the second PLMN.

[0377] Here, the first list and the second list may be included in the system information, and / or the MM message, and / or the SM message, and / or the message sent and received in the procedures of Sections 3.1.2 and 3.1.3.

[0378] The first list may also include one or more PLMN IDs indicating one or more PLMNs to which a disaster state applies. The first list may also be third identification information. The first list may also be a list of PLMNs that are not used for PLMN selection during disaster roaming.

[0379] The second list may also include one or more sets of PLMN IDs indicating PLMNs that support disaster roaming and to which a disaster state does not apply, and signaling overload information for the PLMN IDs or priority information for the PLMN IDs. The second list may be sixth identification information. The second list may be a list of PLMNs to be used for PLMN selection during disaster roaming.

[0380] The signal load information may also indicate whether or not there is a load. Specifically, the signal load information may indicate whether or not there is a load (whether or not there is congestion), or may be a numerical value such as "usage rate: x%."

[0381] Furthermore, the level of priority in the priority information may be indicated by a numerical value, i.e., the lower the numerical value, the higher the priority, or vice versa.

[0382] If the PLMN ID included in the first list indicates the first PLMN, the UE may detect that the first PLMN is in a disaster state and may not perform disaster roaming to the first PLMN.The UE may then identify PLMNs that support disaster roaming and to which a disaster state does not apply based on the PLMN ID included in the second list.The UE may then select a PLMN from the second list that corresponds to signal load information indicating an unloaded state or a PLMN that corresponds to priority information indicating the highest priority value.That is, the UE may not select a PLMN from the first list.

[0383] When selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID not indicated in the first list in the forbidden PLMN list instead of the above selection method. Also, when selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID indicated in the second list in the forbidden PLMN list instead of the above selection method.

[0384] The second list may also be configured to include one or more PLMN IDs indicating PLMNs that support disaster roaming, are not in a disaster state, and are not under load. For example, the second list may be configured in this manner when the network side determines whether the roaming destination PLMN is under load. When selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID included in the second list. That is, the UE does not need to select a PLMN from the first list.

[0385] When selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID not indicated in the first list in the forbidden PLMN list instead of the above selection method. Also, when selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID indicated in the second list in the forbidden PLMN list instead of the above selection method.

[0386] [3.4.2] Here, it is assumed that the UE receives the first list and the second list in the first PLMN (also referred to as PLMN#1) in which the UE is registered when a disaster state applies in the first PLMN.

[0387] Here, the first list and the second list may be included in the system information, and / or the MM message, and / or the SM message, and / or the message sent and received in the procedures of Sections 3.1.2 and 3.1.3.

[0388] The first list may also include one or more PLMN IDs indicating one or more PLMNs to which a disaster state applies. The first list may also be third identification information. The first list may also be a list of PLMNs that are not used for PLMN selection during disaster roaming.

[0389] The second list may also include one or more sets of PLMN IDs indicating PLMNs that support disaster roaming and to which a disaster state does not apply, and signaling overload information for the PLMN IDs or priority information for the PLMN IDs. The second list may be sixth identification information. The second list may be a list of PLMNs to be used for PLMN selection during disaster roaming.

[0390] The signal load information may also indicate whether or not there is a load. Specifically, the signal load information may indicate whether or not there is a load (whether or not there is congestion), or may be a numerical value such as "usage rate: x%."

[0391] Furthermore, the level of priority in the priority information may be indicated by a numerical value, i.e., the lower the numerical value, the higher the priority, or vice versa.

[0392] If the PLMN ID included in the first list indicates the first PLMN, the UE may detect that the first PLMN is in a disaster state and may not perform disaster roaming to the first PLMN.The UE may then identify PLMNs that support disaster roaming and to which a disaster state does not apply based on the PLMN ID included in the second list.The UE may then select a PLMN from the second list that corresponds to signal load information indicating an unloaded state or a PLMN that corresponds to priority information indicating the highest priority value.That is, the UE may not select a PLMN from the first list.

[0393] When selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID not indicated in the first list in the forbidden PLMN list instead of the above selection method. Also, when selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID indicated in the second list in the forbidden PLMN list instead of the above selection method.

[0394] The second list may also be configured to include one or more PLMN IDs indicating PLMNs that support disaster roaming, are not in a disaster state, and are not under load. For example, the second list may be configured in this manner when the network side determines whether the roaming destination PLMN is under load. When selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID included in the second list. That is, the UE does not need to select a PLMN from the first list.

[0395] When selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID not indicated in the first list in the forbidden PLMN list instead of the above selection method. Also, when selecting a PLMN, the UE may select a PLMN indicated by a PLMN ID indicated in the second list in the forbidden PLMN list instead of the above selection method.

[0396] [3.5. Fourth embodiment] The fourth embodiment of the present invention relates to a process for roaming based on the received information when a PLMN to which a UE is registered or connected applies a disaster state and the network notifies the UE of the application of the disaster state. In this procedure, the UE performs roaming based on the received various identification information and SOR-CMCI.

[0397] This embodiment may be implemented by a combination of one or more procedures or processes described in Chapter 3.1, and may also be an embodiment in which, in the registration procedure described in Chapter 3.1.2, the UE sends a registration request message including first identification information to the core network and the message is accepted, or the UE receives an acceptance message including second identification information from the core network.

[0398] In this embodiment, for example, when the UE receives information indicating that the PLMN to which the UE is registered or connected has applied (or released) a disaster state, i.e., the third identification information, included in the notification message through the notification procedure described in Chapter 3.1.3, the timer included in the third identification information and the SOR-CMCI received in advance or together with the notification message is started.

[0399] Here, when roaming from PLMN D to PLMN A, the timer may be started with a value of 0, regardless of the criteria included in the SOR-CMCI. In other words, upon receiving notification of the application of a disaster state from PLMN D, the UE may immediately perform a de-registration procedure and perform roaming based on the combination of PLMN ID and access technology included in the SOR Transparent Container information element.

[0400] Also, for example, when the notification message described in Section 3.1.3 includes a fifth identity in addition to the third identity, the fourth identity, and / or the sixth identity, and receives the fifth identity, the UE may start the timer included in the SOR-CMCI based on the reception of the fifth identity. Subsequently, the UE may perform a de-registration procedure based on the expiration of the timer, and may perform a registration procedure to the PLMN indicated by the fifth identity. In this case, PLMN selection may or may not be performed, and may be determined based on the fifth identity.

[0401] Furthermore, when the UE is registered or connected to an HPLMN, the SOR-CMCI may be received from the HPLMN's UDM via AMF, or when the UE is registered or connected to a VPLMN, the SOR-CMCI may be received from the HPLMN's UDM via AMF within the VPLMN and / or VPLMN.

[0402] 4. Variations A program running on an apparatus according to the present invention may be a program that controls a central processing unit (CPU) or the like to cause a computer to function so as to realize the functions of an embodiment according to the present invention. The program or information handled by the program is temporarily stored in a volatile memory such as a random access memory (RAM), a non-volatile memory such as a flash memory, a hard disk drive (HDD), or another storage device system.

[0403] A program for implementing the functions of the embodiments of the present invention may be recorded on a computer-readable recording medium. The program may be read into a computer system and executed. The term "computer system" as used herein refers to a computer system built into a device, including hardware such as an operating system and peripheral devices. The term "computer-readable recording medium" may also refer to a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a medium that dynamically stores a program for a short period of time, or any other computer-readable recording medium.

[0404] Additionally, each functional block or feature of the device used in the above-described embodiments may be implemented or performed by an electrical circuit, such as an integrated circuit or multiple integrated circuits. The electrical circuit designed to perform the functions described herein may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The general-purpose processor may be a microprocessor, or a conventional processor, controller, microcontroller, or state machine. The electrical circuit may be composed of digital circuits or analog circuits. Furthermore, as advances in semiconductor technology emerge that replace current integrated circuits, one or more aspects of the present invention may utilize new integrated circuits based on that technology.

[0405] The present invention is not limited to the above-described embodiment. Although one example of a device has been described in the embodiment, the present invention is not limited to this and can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as terminal devices or communication devices for AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0406] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the invention. Furthermore, the present invention is susceptible to various modifications within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, configurations in which elements described in the above embodiments are substituted with elements that achieve the same effect are also included.

Claims

1. A UE (User Equipment), A transmitter / receiver and a controller are provided, The transmitting / receiving unit receiving first identification information from a core network in a first procedure while registered with a first PLMN (Public Land Mobile Network); The control unit adding the first PLMN to a list managing barred PLMNs based on receiving the first identification information; The first identification information is identification information indicating that the first PLMN has applied a disaster state. A UE characterized by:

2. the transceiver unit transmits second identification information to a core network in a registration procedure with the first PLMN; The second identification information is identification information indicating the capability of the UE to process the first identification information. The UE according to claim 1, characterized in that:

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